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Complete 911 Timeline

World Trade Center Investigation

Project: Complete 911 Timeline
Open-Content project managed by matt, Paul, KJF, mtuck, paxvector

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A 1968 advert with an artist’s rendition of a plane hitting the WTC.A 1968 advert with an artist’s rendition of a plane hitting the WTC. [Source: Committee for a Reasonable World Trade Center]A civic group opposed to the building of the World Trade Center publishes a nearly full-page advertisement in the New York Times, warning that the new buildings will be so tall that a commercial airliner might crash into them. The group, called the Committee for a Reasonable World Trade Center, is mainly composed of New York real estate developers who are worried that the huge construction project will glut the market. Its leader is Lawrence A. Wien, a real estate mogul who is an owner of the Empire State Building in New York. [New York Times Magazine, 9/8/2002; New York Times Magazine, 9/8/2002] In July 1945, a B-25 Army bomber struck the Empire State Building, killing 14 people. [New York Times, 2/26/1981] The committee’s advertisement shows an artist’s rendition of a large jet plane about to strike one of the proposed towers. [New York Times Magazine, 9/8/2002; New York Times Magazine, 9/8/2002]

Entity Tags: Lawrence A. Wien

Category Tags: WTC Investigation

In the wake of the WTC bombing, the Seattle Times interviews John Skilling who was one of the two structural engineers responsible for designing the Trade Center. Skilling recounts his people having carried out an analysis which found the Twin Towers could withstand the impact of a Boeing 707. He says, “Our analysis indicated the biggest problem would be the fact that all the fuel (from the airplane) would dump into the building. There would be a horrendous fire. A lot of people would be killed.” But, he says, “The building structure would still be there.” [Seattle Times, 2/27/1993] The analysis Skilling is referring to is likely one done in early 1964, during the design phase of the towers. A three-page white paper, dated February 3, 1964, described its findings: “The buildings have been investigated and found to be safe in an assumed collision with a large jet airliner (Boeing 707—DC 8) traveling at 600 miles per hour. Analysis indicates that such collision would result in only local damage which could not cause collapse or substantial damage to the building and would not endanger the lives and safety of occupants not in the immediate area of impact.” However, besides this paper, no documents are known detailing how this analysis was made. [Glanz and Lipton, 2004, pp. 131-132; Lew, Bukowski, and Carino, 10/2005, pp. 70-71] The other structural engineer who designed the towers, Leslie Robertson, carried out a second study later in 1964, of how the towers would handle the impact of a 707 (see Between September 3, 2001 and September 7, 2001). However, the National Institute of Standards and Technology (NIST), following its three-year investigation into the WTC collapses, will in 2005 state that it has been “unable to locate any evidence to indicate consideration of the extent of impact-induced structural damage or the size of a fire that could be created by thousands of gallons of jet fuel.” [National Institute of Standards and Technology, 9/2005, pp. 13]

Entity Tags: World Trade Center, John Skilling

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation

On March 10, Nidal Ayyad is arrested for a role in the February 1993 World Trade Center bombing (see February 26, 1993). Investigators soon discover a letter threatening future attacks in a computer file that was deleted but recovered. It makes reference to an earlier letter sent by Ayyad to the New York Times taking credit for the bombing (see March 2, 1993), and says: “We are the Liberation Army Fifth Battalion again. Unfortunately, our calculations were not very accurate this time. However, we promise you that next time it will be very precise and WTC will continue to be one our targets in the US unless our demands are met.” The letter is signed by the same long Arabic alias used in Ayyad’s previous letter. [New York Times, 12/15/1993]

Entity Tags: Nidal Ayyad

Category Tags: WTC Investigation, Ramzi Yousef, 1993 WTC Bombing

Marvin Bush.Marvin Bush. [Source: Eric Draper / White House]A security company called Stratesec acquires an $8.3 million contract to help provide security at the World Trade Center. It is one of numerous contractors hired in the upgrade of security at the WTC following the 1993 bombing. Stratesec, which was formerly called Securacom, is responsible for installing the “security-description plan”—the layout of the electronic security system—at the World Trade Center. It has a “completion contract” to provide some of the center’s security “up to the day the buildings fell down,” according to Barry McDaniel, its CEO.
Involved with Airport Security - Another of Stratesec’s biggest security contracts, between 1995 and 1998, is with the Metropolitan Washington Airport Authority, providing electronic security for Reagan National Airport and Dulles International Airport. Its work includes maintaining the airfield access systems, the CCTV (closed circuit television) systems, and the electronic badging systems. American Airlines Flight 77—one of the planes hijacked on 9/11—takes off from Dulles.
Directors Include Bush Family Member - Marvin P. Bush, the youngest brother of future President George W. Bush, is a director at Stratesec from 1993 to June 2000, when most of its work on these big projects is done. Wirt D. Walker III, a distant relative of George W. Bush, is chairman of the board at Stratesec from 1992, and its CEO from 1999 until January 2002. Another of Stratesec’s directors, from 1991 to 2001, is Mishal Yousef Saud Al Sabah, who is a member of the Kuwaiti royal family. Al Sabah is also chairman of an investment company called the Kuwait-American Corporation (KuwAm), which, between 1993 and 1999, holds a large, often controlling share of Stratesec. In 1996, it owns 90 percent of the company; by 1999 it owns 47 percent.
Other Interests - Walker and Al Sabah are also co-investors in two inter-related aviation companies: Aviation General and Commander Aircraft. According to a 2005 report by freelance journalist Margie Burns: “Aviation General boasted of its international clientele. A 1996 press release announced its sale of airplanes to the National Civil Aviation Training Organization (NCATO) of Giza, Egypt, ‘the sole civilian pilot training organization in Egypt.’ The announcement mentions Al Sabah as chairman of KuwAm and board member of Commander Aircraft Company.” NCATO also has contractual partnerships with several US flight schools, including Embry-Riddle University in Florida.
Connections with Foreign Company a Delicate Matter - According to Wayne Black, the head of a Florida-based security firm, it is delicate for a security company serving international facilities to be so interlinked with a foreign-owned company. He suggests, “Somebody knew somebody.” Black also points out that when a company has a security contract, “you know the inner workings of everything.” Furthermore, if another company is linked to the security company, then “what’s on your computer is on their computer.” After 9/11 Stratesec CEO Barry McDaniel will be asked whether FBI or other agents have questioned him or others at Stratesec about their security work related to 9/11. He answers, “No.” [American Reporter, 1/20/2003; Prince George's Journal, 2/4/2003; Progressive Populist, 3/1/2003; Progressive Populist, 4/15/2003; Washington Spectator, 2/15/2005] Other companies involved with the security overhaul during this time include Ensec Inc., which is in charge of creating a new parking access control system, E-J Electric Installation Co., and Electronic Systems Associates, a division of Syska Hennessy. [Access Control & Security Systems, 7/1/1997; CEE News, 1/1/2001; CEE News, 10/1/2001; Building Design and Construction, 7/1/2002]

Entity Tags: Mishal Yousef Saud Al Sabah, Kuwait-American Corporation (KuwAm), Marvin Bush, Stratesec, Ronald Reagan Washington National Airport, World Trade Center, Wirt D. Walker III, Washington Dulles International Airport, Ensec, Inc., Embry-Riddle University, National Civil Aviation Training Organization, E-J Electric Installation Co., Commander Aircraft, Aviation General, Electronic Systems Associates

Category Tags: US Air Security, WTC Investigation

It is later revealed that, in the years up to 9/11, New York City Mayor Rudolph Giuliani has little knowledge of the threat posed by al-Qaeda. [MSNBC, 10/25/2007] In private testimony before the 9/11 Commission in 2004, after being asked about the “flow of information about al-Qaeda threats from 1998-2001,” Giuliani will reply, “At the time, I wasn’t told it was al-Qaeda, but now that I look back at it, I think it was al-Qaeda.” Giuliani will also concede that it was only “after 9/11” that “we brought in people to brief us on al-Qaeda.” Before 9/11, he says, “we had nothing like this… which was a mistake, because if experts share a lot of info,” there would be a “better chance of someone making heads and tails” of the situation. [Village Voice, 10/23/2007] In a later television interview, he will admit that he “didn’t see the enormity of” the threat al-Qaeda posed to the United States prior to 9/11, and add: “I never envisioned the kind of attack that they did.… [W]hat I envisioned were the kind of suicide bombings that had gone on in, in Israel. I had been briefed on that.… But I had no idea of the kind of level of attack that was in store for us.” [MSNBC, 12/9/2007] He blames his lack of knowledge on terrorism partly on the FBI and the Joint Terrorism Task Force (JTTF), a partnership between the FBI and the New York City Police Department. Giuliani will state: “We already had JTTF, and got flow information no one else got. But did we get the flow of information we wanted? No. We would be told about a threat, but not about the underlying nature of the threat. I wanted all the same information the FBI had, and we didn’t get that until after 9/11.” [Village Voice, 10/23/2007] He will also complain, “I was dependent on the briefings that I was getting from… the [Clinton] administration, and… I don’t think they saw the threat as big as it was.” [MSNBC, 12/9/2007] In 2004, the 9/11 Commission asks Thomas Von Essen, who is Giuliani’s fire commissioner, what information he had about terrorism prior to 9/11. He will reply, “I was told nothing at all.” Yet in a speech in 2007, Giuliani will claim that, with the 1993 World Trade Center bombing: “Bin Laden declared war on us.… I thought it was pretty clear at the time, but a lot of people didn’t see it, couldn’t see it.” He also claims to have been “studying terrorism” for more than 30 years. [Associated Press, 6/26/2007; Village Voice, 10/23/2007]

Entity Tags: Rudolph (“Rudy”) Giuliani, Joint Terrorism Task Force, Federal Bureau of Investigation, Al-Qaeda, Thomas Von Essen

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation

Giuliani’s emergency command center.Giuliani’s emergency command center. [Source: CNN]New York City Mayor Rudolph Giuliani opens a $13 million emergency command center on the 23rd floor of World Trade Center Building 7. [Newsday, 9/12/2001] The center is intended to coordinate responses to various emergencies, including natural disasters like hurricanes or floods, and terrorist attacks. The 50,000 square foot center has reinforced, bulletproof, and bomb-resistant walls, its own air supply and water tank, beds, showers to accommodate 30 people, and three backup generators. It also has rooms full of video monitors from where the mayor can oversee police and fire department responses. It is to be staffed around the clock and is intended as a meeting place for city leaders in the event of an act of terrorism. [CNN, 6/7/1999; London Times, 9/12/2001; Glanz and Lipton, 2004, pp. 233] The center is ridiculed as “Rudy’s bunker.” [Time, 12/22/2001] Author Philip Shenon will later comment that it “seemed the supreme example of how Giuliani’s ego and arrogance knew no bounds after four years in office,” and: “WABC Radio mocked Giuliani with a name-that-bunker contest for its listeners. Among the most popular entries: ‘Rudy’s Nuclear Winter Palace’ and ‘The Nut Shell.’” It is criticized because of the cost and because of the location, next to the WTC towers, one of the city’s top terrorist targets. In addition, the high floor it is on means it is vulnerable to power, water, and elevator outages. [Shenon, 2008, pp. 346-347] Most controversial is the 6,000-gallon fuel tank. In 1998 and 1999, Fire Department officials warn that the fuel tank violates city fire codes and poses a hazard. According to one Fire Department memorandum, if the tank were to catch fire it could produce “disaster.” Building 7 will be destroyed late in the day on 9/11; some suspect this tank helps explains why. [New York Times, 12/20/2001]

Entity Tags: Rudolph (“Rudy”) Giuliani, Office of Emergency Management, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: Counterterrorism Policy/Politics, WTC Investigation

The North Tower of the WTC suffers a fire on its 104th floor. This is the 15th and last of what the National Institute of Standards and Technology later describes as “significant fires,” which occurred in the Twin Towers from 1975 onwards, and prior to 9/11. These fires each activate up to three sprinklers but are confined to just one floor. [Kuligowski, Evans, and Peacock, 9/2005, pp. 7-11] Additionally, on February 14, 1975 a major fire occurred, the result of arson, which began on the 11th floor of the North Tower during the middle of the night. Spreading through floor openings in the utility closets, it caused damage from the 10th to 19th floors, though this was generally confined to the utility closets. However, on the 11th floor about 9,000 square feet was damaged. This was about 21 percent of the floor’s total area (43,200 square feet) and took weeks to repair. Some parts of the steel trusses (floor supports) buckled due to the heat. 132 firefighters were called to the tower in response, and because the fire was so hot, many got their necks and ears burned. Fire Department Captain Harold Kull described the three-hour effort to extinguish it as “like fighting a blowtorch.” [WTC Environmental Assessment Working Group, 9/2002, pp. 10 pdf file; New York Times, 5/8/2003; Glanz and Lipton, 2004, pp. 213, 214, 324; Kuligowski, Evans, and Peacock, 9/2005, pp. 1] An article in Fire Engineering magazine will later summarize, “[A]lmost all large buildings will be the location for a major fire in their useful life. No major high-rise building has ever collapsed from fire. The WTC was the location for such a fire in 1975; however, the building survived with minor damage and was repaired and returned to service.” [Fire Engineering, 10/2002] Building 7 of the WTC, which completely collapses late in the afternoon on 9/11, has also suffered a ‘significant’ fire in 1988, occurring on its third floor, with multiple sprinklers being activated. [Kuligowski, Evans, and Peacock, 9/2005, pp. 12]

Entity Tags: World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation

Frank De Martini.Frank De Martini. [Source: New York Times]Frank De Martini, an architect who works as the World Trade Center’s construction manager, is interviewed for a History Channel documentary about the WTC towers. He says, “I believe the building probably could sustain multiple impacts of jetliners because this structure is like the mosquito netting on your screen door, this intense grid, and the jet plane is just a pencil puncturing the screen netting. It really does nothing to the screen netting.” [Dwyer and Flynn, 2005, pp. 149] De Martini will be in his office on the 88th floor of the North Tower when it is hit on 9/11. He will die when the tower collapses, after helping more than 50 people escape. [Associated Press, 8/29/2003; New York Times, 8/29/2003]

Entity Tags: Frank De Martini, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation

A property risk assessment report is prepared for Silverstein Properties before it acquires the lease for the World Trade Center (see July 24, 2001). It identifies the scenario of an aircraft hitting one of the WTC towers as one of the “maximum foreseeable losses.” The report says, “This scenario is within the realm of the possible, but highly unlikely.” Further details of the assessment, such as who prepared it, are unreported. [National Institute of Standards and Technology, 5/2003, pp. 16 pdf file; Barrett and Collins, 2006, pp. 189; American Prospect, 9/1/2006]

Entity Tags: Silverstein Properties, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Related Lawsuits

Larry Silverstein.
Larry Silverstein. [Source: Silverstein Properties publicity photo]Real estate development and investment firm Silverstein Properties and real estate investment trust Westfield America Inc. finalize a deal worth $3.2 billion to purchase a 99-year lease on the World Trade Center. The agreement covers the Twin Towers, World Trade Center Buildings 4 and 5 (two nine-story office buildings), and about 425,000 square feet of retail space. [New York Times, 4/27/2001; Port Authority of New York and New Jersey, 7/24/2001; IREIzine, 7/26/2001] Westfield America Inc. will be responsible for the retail space, known as the Mall. Silverstein Properties’ lease will cover the roughly 10 million square feet of office space of the Twin Towers and Buildings 4 and 5. Silverstein Properties already owns Building 7 of the WTC, which it built in 1987. This is the only time the WTC has ever changed hands since it was opened in 1973. [International Council of Shopping Centers, 4/27/2001; Westfield Group, 7/24/2001; Daily Telegraph, 9/11/2001; New York Times, 11/29/2001; CNN, 8/31/2002] It was previously controlled by the New York Port Authority, a bi-state government agency. [Wall Street Journal, 5/12/2007] Silverstein and Westfield are given the right to rebuild the structures if they are destroyed. [New Yorker, 5/20/2002]
Silverstein Properties Not the Highest Bidder - Silverstein Properties’ bid for the WTC, at $3.22 billion, was the second highest after Vornado Realty Trust’s, at $3.25 billion. Silverstein Properties won the contract only after protracted negotiations between the Port Authority and Vornado Realty Trust failed. The privatization of the WTC has been overseen by Lewis M. Eisenberg, the chairman of the Port Authority. Eisenberg, a financier, is involved in Republican politics. [New York Times, 3/17/2001; Forward, 8/20/2004]
Banks Provide Most Money for Deal - Larry Silverstein, the president of Silverstein Properties, only uses $14 million of his own money for the deal. His partners, who include real estate investors Lloyd Goldman and Joseph Cayre, put up a further $111 million, and banks provide $563 million in loans. [Brill, 2003, pp. 156; New York Times, 11/22/2003; South Florida CEO, 2/2005; Wall Street Journal, 9/11/2008]
Silverstein's Lenders Want More Insurance - The Port Authority had carried only $1.5 billion in insurance coverage on all its buildings, including the WTC, but Silverstein’s lenders insist on more, eventually demanding $3.55 billion in cover. [American Lawyer, 9/3/2002] After 9/11, Larry Silverstein will claim the attacks on the World Trade Center constituted two separate events, thereby entitling him to a double payout totaling over $7 billion. [Daily Telegraph, 10/9/2001; Guardian, 8/18/2002] Eventually, after several years of legal wrangling, a total of $4.55 billion of insurance money will be paid out for the destruction of the WTC (see May 23, 2007). Most of this appears to go to Silverstein Properties. How much goes to Westfield America Inc. is unclear. [New York Post, 5/24/2007]

Entity Tags: Vornado Realty Trust, Larry Silverstein, Joseph P. Cayre, Lewis M. Eisenberg, Lloyd Goldman, Port Authority of New York and New Jersey, Westfield America, World Trade Center, Silverstein Properties

Timeline Tags: 9/11 Timeline

Category Tags: 9/11 Related Lawsuits, WTC Investigation

Alan Reiss.Alan Reiss. [Source: Eric Weeks]In the first week of September 2001, the real estate development and investment firm Silverstein Properties assumes control of the World Trade Center. The company had acquired the lease to operate the Twin Towers from the New York Port Authority in late July (see July 24, 2001). It has already begun managing the facility with its own executives. Selected Port Authority employees, including Alan Reiss, the director of the World Trade Center, have been assisting the firm during a three-month transition period. But in the weeks prior to 9/11, according to the New York Times, “Silverstein Properties asked Mr. Reiss to let it more fully operate everything from safety systems to tenant relations.” [New York Times, 9/13/2001; New York Times, 10/14/2001; Weiss, 2003, pp. 338; 9/11 Commission, 11/3/2003; 9/11 Commission, 5/18/2004 pdf file]

Entity Tags: Alan Reiss, Silverstein Properties, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: 9/11 Related Lawsuits, WTC Investigation

Leslie Robertson.Leslie Robertson. [Source: Publicity photo]Leslie Robertson, one of the two original structural engineers for the World Trade Center, is asked at a conference in Frankfurt, Germany what he had done to protect the Twin Towers from terrorist attacks. He replies, “I designed it for a 707 to smash into it,” though does not elaborate further. [Chicago Tribune, 9/12/2001; Knight Ridder, 9/12/2001] The Twin Towers were in fact the first structures outside the military and nuclear industries designed to resist the impact of a jet airplane. [Robertson, 3/2002; Federal Emergency Management Agency, 5/1/2002, pp. 1-17] The Boeing 707 was the largest in use when the towers were designed. Robertson conducted a study in late 1964, to calculate the effect of a 707 weighing 263,000 pounds and traveling at 180 mph crashing into one of the towers. He concluded that the tower would remain standing. However, no official report of his study has ever surfaced publicly. [Glanz and Lipton, 2004, pp. 138-139, 366] A previous analysis, carried out early in 1964, calculated that the towers would handle the impact of a 707 traveling at 600 mph without collapsing (see February 27, 1993). In 2002, though, Robertson will write, “To the best of our knowledge, little was known about the effects of a fire from such an aircraft, and no designs were prepared for that circumstance.” [Robertson, 3/2002] The planes that hit the WTC on 9/11 are 767s, which are almost 20 percent heavier than 707s. [Scientific American, 10/9/2001; New Yorker, 11/19/2001]

Entity Tags: Leslie Robertson, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation

Former FBI counterterrorism chief John O’Neill recently started his new job as director of security at the World Trade Center (see August 23, 2001). From the outset, he has engrossed himself in discovering what security systems are in place there, and what will be needed in future. On this day, he runs into Rodney Leibowitz, a friend of his, and complains to him about the very poor standard of security at the Twin Towers. For instance, he mentions that, even though the complex receives bomb threats on a daily basis, its telephone system does not feature caller identification. [Weiss, 2003, pp. 354 and 358] The Trade Center has in fact recently been on a heightened security alert, due to numerous phone threats (see Late August-September 10, 2001). [Newsday, 9/12/2001] Leibowitz is the president and CEO of a company called First Responder Inc., which provides bioterrorism preparedness training to healthcare professionals. [First Responder Inc., 1/14/2004] Until the 9/11 attacks intervene, First Responder Inc. is in fact scheduled to send in a team to conduct a threat assessment of the World Trade Center for O’Neill on September 15. [Swanson, 2003, pp. 52]

Entity Tags: John O’Neill, First Responder Inc., World Trade Center, Rodney Leibowitz

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, Counterterrorism Policy/Politics

Silverstein Properties, Larry Silverstein’s company which took over the lease of the WTC weeks earlier (see July 24, 2001), has a meeting planned for the morning of 9/11 in it’s temporary offices on the 88th floor of the WTC North Tower, along with Port Authority officials. It is to discuss what to do in the event of a terrorist attack. However, this evening the meeting is canceled because one participant cannot attend. [New York Times, 9/12/2001; Ha'aretz, 11/21/2001] Of Silverstein Properties’ 160 staff, 54 are in the North Tower when it is hit, and four of them die. [Globe and Mail, 9/7/2002]

Entity Tags: Larry Silverstein, Silverstein Properties, Port Authority of New York and New Jersey

Timeline Tags: 9/11 Timeline

Category Tags: Other Pre-9/11 Events, WTC Investigation

According to later reports, the alarm system in WTC 7 is placed on “TEST” status for a period due to last eight hours. This ordinarily happens during maintenance or other testing, and any alarms received from the building are generally ignored. [National Institute of Standards and Technology, 6/2004, pp. 28 pdf file]

Entity Tags: World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center

The hole caused by the Flight 11 crash.The hole caused by the Flight 11 crash. [Source: Reuters]Flight 11 slams into the WTC North Tower (Building 1). Hijackers Mohamed Atta Waleed Alshehri, Wail Alshehri, Abdulaziz Alomari, and Satam Al Suqami presumably are killed instantly, and many more in the tower will die over the next few hours. Seismic records pinpoint the crash at 26 seconds after 8:46 a.m. [CNN, 9/12/2001; New York Times, 9/12/2001; North American Aerospace Defense Command, 9/18/2001; USA Today, 12/20/2001; Federal Emergency Management Agency, 5/1/2002, pp. 1-10; New York Times, 5/26/2002; USA Today, 8/13/2002; Associated Press, 8/21/2002; Newsday, 9/10/2002] The NIST report states the crash time to be 8:46:30. [National Institute of Standards and Technology, 9/2005, pp. 19] The 9/11 Commission Report states the crash time to be 8:46:40. [9/11 Commission, 7/24/2004, pp. 7] Investigators believe the plane still has about 10,000 gallons of fuel (see 8:57 a.m. September 11, 2001). [New York Times, 5/26/2002] The plane strikes the 93rd through 99th floors in the 110-story building. No one above the crash line survives; approximately 1,360 people die. Below the crash line, approximately 72 die and more than 4,000 survive. Both towers are slightly less than half full at the time of the attack, with between 5,000 to 7,000 people in each tower. This number is lower than expected. Many office workers have not yet shown up to work, and tourists to the observation deck opening at 9:30 A.M. have yet to arrive. [USA Today, 12/20/2001; National Institute of Standards and Technology, 9/2005, pp. 20-22] The impact severs some columns on the north side of the North Tower. Each tower is designed as a “tube-in-tube” structure and the steel columns which support its weight are arranged around the perimeter and in the core. The plane, which weighs 283,600 lb and is traveling at an estimated speed of around 430 mph (see October 2002-October 2005), severs 35 of the building’s 236 perimeter columns and damages another two. The damage to the South Tower’s perimeter will be similar (see 9:03 a.m. September 11, 2001). [National Institute of Standards and Technology, 9/2005, pp. 5-9, 20, 22] The perimeter columns bear about half of the tower’s weight, so this damage reduces its ability to bear gravity loads by about 7.5 percent. [National Institute of Standards and Technology, 9/2005, pp. 6] The actual damage to the 47 core columns is not known, as there are no photographs or videos of it, but there will be much speculation about this after 9/11. It will be suggested that some parts of the aircraft may have damaged the core even after crashing through the exterior wall. According to the National Institute of Standards and Technology (NIST): “Moving at 500 mph, an engine broke any exterior column it hit. If the engine missed the floor slab, the majority of the engine core remained intact and had enough residual momentum to sever a core column upon direct impact.” [National Institute of Standards and Technology, 9/2005, pp. 107] According to NIST’s base case computer model, three of the core columns are severed and another ten suffer some damage. [National Institute of Standards & Technology, 9/2005, pp. 189 pdf file] If this is accurate, it means that the impact damage to the core reduces the Tower’s strength by another approximately 7.5 percent, meaning that the building loses about 15 percent of its strength in total. This damage will be cited after 9/11 by NIST and others researchers as an event contributing to the building’s collapse (see October 23, 2002 and October 19, 2004). In addition, some of the fireproofing on the steel columns and trusses may be dislodged. The original fireproofing on the fire floors was mostly Blazeshield DC/F, but some of the fireproofing on the flooring has recently been upgraded to Blazeshield II, which is about 20 percent denser and 20 percent more adhesive. [National Institute of Standards & Technology, 9/2005, pp. xxxvi, 83 pdf file] Photographs and videos of the towers will not show the state of fireproofing inside the buildings, but NIST will estimate the damage to it using a computer model. Its severe case model (see (October 2002-October 2005)) will predict that 43 of the 47 core columns are stripped of their fireproofing on one or more floors and that fireproofing is stripped from trusses covering 60,000 ft2 of floor area, the equivalent of about one and a half floors. NIST will say that the loss of fireproofing is a major cause of the collapse (see April 5, 2005), but only performs 15 tests on fireproofing samples (see October 26, 2005). [National Institute of Standards and Technology, 9/2005, pp. 23] According to NIST, more fireproofing is stripped from the South Tower (see 9:03 a.m. September 11, 2001).

Entity Tags: Mohamed Atta, National Institute of Standards and Technology, Satam Al Suqami, Waleed Alshehri, Abdulaziz Alomari, World Trade Center, Wail Alshehri

Timeline Tags: 9/11 Timeline

Category Tags: Key Day of 9/11 Events, All Day of 9/11 Events, Flight AA 11, Flight UA 175, George Bush, World Trade Center, Mohamed Atta, Other 9/11 Hijackers, WTC Investigation

Mike Pecoraro.Mike Pecoraro. [Source: Chief Engineer]Mike Pecoraro, an engineer who is part of the crew that services the WTC complex, is at work in the mechanical shop in the second subbasement of the north WTC tower when it is hit. When the room he is in starts filling with white smoke and he can smell kerosene (jet fuel), he heads up stairs with a co-worker towards a small machine shop on the C level. Yet, he says, “There was nothing there but rubble. We’re talking about a 50 ton hydraulic press—gone!” He then heads for the parking garage, yet finds that “there were no walls, there was rubble on the floor, and you can’t see anything.” He ascends to the B level where he sees a 300-pound steel and concrete fire door, which is lying on the floor, wrinkled up “like a piece of aluminum foil.” Pecoraro recalls seeing similar things at the Center when it was bombed in 1993 and is therefore convinced that a bomb has gone off this time. When he makes it into the main lobby, he sees massive damage: “The whole lobby was soot and black, elevator doors were missing. The marble was missing off some of the walls. 20-foot section of marble, 20 by 10 foot sections of marble, gone from the walls.… Broken glass everywhere, the revolving doors were all broken and their glass was gone.” Pecoraro says he only later hears that “jet fuel actually came down the elevator shaft, blew off all the (elevator) doors and flames rolled through the lobby. That explained all the burnt people and why everything was sooted in the lobby.” He makes it out of the North Tower before it collapses. [Chief Engineer, 8/1/2002]

Entity Tags: Mike Pecoraro, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center, 9/11 Investigations

The jet fuel that spilled from Flight 11 when it hit the North Tower (see 8:46 a.m. September 11, 2001) has mostly burned up by this time. The National Institute of Standards and Technology (NIST), which investigates the collapses, will say “The initial jet fuel fires themselves lasted at most a few minutes.” [National Institute of Standards and Technology, 9/2005, pp. 183] Engineering professor Forman Williams will say the jet fuel “burned for maybe 10 minutes.” [Popular Mechanics, 3/2005] Flight 11, a Boeing 767, had a fuel capacity of 23,980 gallons, but was only carrying about 10,000 gallons when it hit the WTC. NIST will estimate that less than 1,500 gallons were consumed in a fireball inside the tower and a comparable amount was consumed in the fireballs outside the building. Therefore, approximately 7,000 gallons splashed onto the office furnishings and started fires on various floors. However, after the jet fuel is used up, office fires burn until the building collapses. NIST will calculate that there were about four pounds per square foot of combustibles in the office space, or about 60 tons per floor. Offices in the WTC actually have fewer combustibles than some other similar spaces due to the small number of interior walls and limited bookshelf space. NIST will later find that only three of sixteen perimeter columns it recovers reached a temperature of 250°C and neither of the two core columns it retrieves reached this temperature. NIST will also find that none of the samples it acquires reaches a temperature above 600°C (see August 27, 2003). Although steel does not melt until its temperature is about 1,600°C, it may begin to lose significant strength at over 500°C. [National Institute of Standards and Technology, 9/2005, pp. 20, 29, 24, 77] The jet fuel will also burn up in the South Tower about 10 minutes after it is hit (see 9:13 a.m. September 11, 2001).

Entity Tags: Forman Williams, World Trade Center, National Institute of Standards and Technology

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center

Flight 175 hits the WTC South Tower. The picture was taken from a traffic helicopter.Flight 175 hits the WTC South Tower. The picture was taken from a traffic helicopter. [Source: WABC 7/ Salient Stills]Flight 175 hits the South Tower of the World Trade Center (Tower Two). Seismic records pinpoint the time at six seconds before 9:03 a.m. (rounded to 9:03 a.m.). Hijackers Marwan Alshehhi, Fayez Ahmed Banihammad, Mohand Alshehri, Hamza Alghamdi, and Ahmed Alghamdi presumably are killed instantly, and many more in the tower will die over the next few hours. [New York Times, 9/12/2001; CNN, 9/12/2001; CNN, 9/17/2001; North American Aerospace Defense Command, 9/18/2001; USA Today, 12/20/2001; Federal Emergency Management Agency, 5/1/2002, pp. 1-10; New York Times, 5/26/2002; Associated Press, 8/21/2002; USA Today, 9/2/2002] According to the NIST report, the crash time is 9:02:59. [National Institute of Standards and Technology, 9/2005, pp. 38] According to the 9/11 Commission Report, the crash time is 9:03:11. [9/11 Commission, 7/24/2004, pp. 8] Millions watch the crash live on television. The plane strikes the 77th through 85th floors in the 110-story building. Approximately 100 people are killed or injured in the initial impact; 600 people in the tower eventually die. The death toll is far lower than in the North Tower because about two-thirds of the South Tower’s occupants have evacuated the building in the 17 minutes since the first tower was struck. [USA Today, 12/20/2001; National Institute of Standards and Technology, 9/2005, pp. 5-9, 41] The combined death toll from the two towers is estimated at 2,819, not including the hijackers. [Associated Press, 8/21/2002] The impact severs some columns on the south side of the South Tower. Each of the Twin Towers is designed as a “tube-in-tube” structure and the steel columns which support its weight are arranged around the perimeter and in the core. The plane, which is traveling at an estimated speed of around 500 mph (see October 2002-October 2005), severs 33 of the building’s 236 perimeter columns and damages another one. [National Institute of Standards and Technology, 9/2005, pp. 39] The perimeter columns bear about half of the tower’s weight, so the damage to them reduces the tower’s ability to bear gravity loads by about 7.1 percent. [National Institute of Standards and Technology, 9/2005, pp. 6] The actual damage to the 47 core columns is not known, as there are no photographs or videos of it, but there will be much speculation about this after 9/11. It will be suggested that some parts of the aircraft may be able to damage the core even after crashing through the exterior wall (see 8:46 a.m. September 11, 2001). [National Institute of Standards and Technology, 9/2005, pp. 107] According to NIST’s base case model, five of the core columns are severed and another five suffer some damage. [National Institute of Standards & Technology, 9/2005, pp. 235 pdf file] This may reduce the tower’s ability to bear loads by a further approximately 8 percent, meaning that the aircraft impact accounted for a loss of about 15 percent of the building’s strength. This damage will be cited as an event contributing to the building’s collapse after 9/11 (see October 23, 2002 and October 19, 2004). NIST’s base case estimate of damage to the North Tower’s core will be similar, even though the aircraft impact there was dissimilar (see 8:46 a.m. September 11, 2001). Flight 11 hit the North Tower’s core head on, whereas Flight 175 only hits the corner of the South Tower’s core. [National Institute of Standards and Technology, 9/2005, pp. 20-23, 38-41] In addition, some of the fireproofing on the steel columns and trusses may be dislodged (see 8:46 a.m. September 11, 2001). [National Institute of Standards & Technology, 9/2005, pp. xxxvi, 83 pdf file] Photographs and videos of the towers will not show the state of fireproofing inside the buildings, but the National Institute of Standards and Technology (NIST) will try to estimate the damage to fireproofing using a series of computer models. Its severe case model (see (October 2002-October 2005)) will predict that 39 of the 47 core columns are stripped of their fireproofing on one or more floors and that fireproofing is stripped from trusses covering 80,000 ft2 of floor area, the equivalent of about two floors. NIST will say that the loss of fireproofing is a major cause of the collapse (see April 5, 2005), but only performs 15 tests on fireproofing samples (see October 26, 2005). [National Institute of Standards and Technology, 9/2005, pp. 41] According to NIST, less fireproofing is stripped from the North Tower (see 8:46 a.m. September 11, 2001).

Entity Tags: World Trade Center, Marwan Alshehhi, Fayez Ahmed Banihammad, Hamza Alghamdi, National Institute of Standards and Technology, Ahmed Alghamdi, Mohand Alshehri

Timeline Tags: 9/11 Timeline

Category Tags: Key Day of 9/11 Events, All Day of 9/11 Events, Flight AA 77, Flight UA 175, Flight UA 93, George Bush, World Trade Center, Marwan Alshehhi, Other 9/11 Hijackers, WTC Investigation

Brian Clark.Brian Clark. [Source: CTV]Brian Clark, the executive vice president of brokerage firm Euro Brokers, was on the 84th floor of the South Tower, where his firm’s offices are, when Flight 175 crashed into it. He had headed out, going down Stairway A, which is the only staircase in the tower that remains intact from top to bottom, and was soon joined by Stanley Praimnath, who also works in the South Tower. They reach a point that Clark later guesses to have been around the 77th or 78th floor, where the stairway walls are cracked, allowing them to look through. This would be around the lower end of the floors where the plane impacted. However, Clark sees no large fire. He later says, “[Y]ou could look through the cracks and see flames. They were just quietly licking up, not a roaring inferno. And there was some smoke there, but again I think the stairs were pressurized, pushing the air out so we had less smoke in the stairway than you might imagine.” [BBC, 3/7/2002; New York Times, 5/26/2002; Sun, 9/6/2002; 9/11 Commission, 5/18/2004] This apparently contradicts later claims that the tower was subjected to “extreme fires” prior to its collapse. [New York Times, 10/20/2004] Firefighter Orio Palmer will make it up to this level of the tower later on, and also report only finding small fires there (see 9:52 a.m. September 11, 2001). Clark and Praimnath continue down the stairs and make it out just minutes before the collapse. They are two of only four people who were at or above the impact zone after Flight 175 hit, who are able to escape from the South Tower. [CNN, 9/9/2002] A further 14 people are able to get out of the building from its 78th floor, which is the lower part of the crash zone. [Dwyer and Flynn, 2005, pp. 255]

Entity Tags: Stanley Praimnath, World Trade Center, Brian Clark

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center, 9/11 Investigations

The jet fuel that spilled from Flight 175 when it hit the South Tower (see 9:03 a.m. September 11, 2001) has mostly burned up by this time. The National Institute of Standards and Technology (NIST), which later investigates the collapses, will say the “initial jet fuel fires themselves lasted at most a few minutes.” [National Institute of Standards and Technology, 9/2005, pp. 183] Engineering professor Forman Williams will say the jet fuel “burned for maybe 10 minutes.” [Popular Mechanics, 3/2005] Flight 175, a Boeing 767, had a capacity of 23,980 gallons, but was only carrying about 9,100 gallons of fuel when it hit the WTC. NIST will estimate that less than 1,500 gallons were consumed in a fireball inside the tower and 910 to 2,275 gallons were consumed in the fireballs outside the building. Approximately 6,100 gallons therefore splashed onto the office furnishings and started fires on various floors. However, after the jet fuel is used up, office fires burn until the building collapses. NIST will calculate that there were about four pounds per square foot of combustibles in the office space, or about 60 tons per floor. Offices in the WTC actually had fewer combustibles than other similar spaces due to the small number of interior walls and limited bookshelf space. NIST will later find that only three of sixteen perimeter columns it recovers reached a temperature of 250°C and neither of the two core columns it retrieves reached this temperature. NIST will also find that none of the samples it acquires reached a temperature above 600°C (see August 27, 2003). While steel does not melt until its temperature is about 1,600°C, it may begin to lose significant strength at over 500°C. [National Institute of Standards and Technology, 9/2005, pp. 29, 38, 42, 77] The jet fuel also burned up in the North Tower about 10 minutes after it was hit (see 8:57 a.m. September 11, 2001). When a group of firefighters reach the bottom impact floor in the South Tower just before collapse, they only find two isolated fires (see 9:52 a.m. September 11, 2001).

Entity Tags: World Trade Center, National Institute of Standards and Technology, Forman Williams

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center

The exterior wall on the east side of the World Trade Center’s South Tower apparently bows before the building collapses. The first inquiry into the collapse, by the Federal Emergency Management Agency and the American Society of Civil Engineers, states that the perimeter walls bow outward. “Expansion of floor slabs and framing results in outward deflection of columns and potential overload,” the investigation concludes. [Federal Emergency Management Agency, 5/1/2002, pp. 2-25] However, a subsequent report by the National Institute of Standards and Technology states that the east wall of the South Tower bows inward. In places the wall is said to bow inward by between seven and nine inches at floor 80, and NIST interprets this bowing to mean that the floors must be sagging. NIST will find that the sagging and bowing are two of the seven major factors that led to the collapse of each tower, as the bowing walls are no longer able to support their share of the buildings’ weight, causing the buildings to tilt and the upper sections to fall. [National Institute of Standards and Technology, 9/2005, pp. 43-46, 87] A wall in the North Tower also apparently bows before the building collapses (see 10:23 a.m. September 11, 2001).

Entity Tags: Federal Emergency Management Agency, World Trade Center, National Institute of Standards and Technology

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center

A man who is on the 105th floor of the South Tower calls emergency 9-1-1 to report that floors below his location, “in the 90-something floor,” have collapsed. The 9-1-1 operator types a record of this call into the Special Police Radio Inquiry Network (SPRINT) data link, which will be passed on to the New York fire department’s Emergency Medical Service (EMS). It isn’t known when the call is made exactly, but the EMS Dispatch computer apparently receives the call record at this time. However, because it is classified as a “supplement message,” it is not yet read by anyone. The police dispatcher dealing with the area around the WTC also receives the call record, but misinterprets it as meaning that the floor the person is on has collapsed. EMS dispatchers are dealing with an enormous volume of calls as well as performing many other tasks under extreme pressure during the crisis, so a report later concludes that the EMS operators didn’t have the time to review the information before the collapse of the South Tower at 9:59 (see 9:59 a.m. September 11, 2001), and the fire chiefs never received the information. [New York City Fire Department, 8/19/2002]

Entity Tags: World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center

Molten metal pouring out of the side of the World Trade Center.Molten metal pouring out of the side of the World Trade Center. [Source: Cameraplanet]Video footage later reveals that in the minutes immediately before the collapse of the WTC’s South Tower, a stream of molten metal starts pouring out of a window opening around the northeast corner of its 80th floor. FEMA later suggests that this is “possibly aluminum from the airliner,” and comments, “This is of particular interest because, although the building collapse appears to have initiated at this floor level, the initiation seems to have occurred at the southeast rather than the northeast corner.” [Civil Engineering, 5/2002; Federal Emergency Management Agency, 5/1/2002, pp. 2-34; Dwyer and Flynn, 2005, pp. 207] According to the National Institute of Standards and Technology, “The composition of the flowing material can only be the subject of speculation, but its behavior suggests it could have been molten aluminum.” [Pitts, Butler, and Junker, 9/2005, pp. 375] However physics professor Steven E. Jones will in 2006 dispute this, saying that molten aluminum is silvery and never turns yellow, like what is in the video footage. He will instead claim the presence of this molten metal supports the theory that explosives, specifically thermite, are what caused the Twin Towers to collapse. He says thermite can cause steel to melt and become yellowish. [Deseret Morning News, 4/10/2006]

Entity Tags: World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center

Ronald Bucca.
Ronald Bucca. [Source: Public domain]Two firefighters climbing up the South Tower, Orio Palmer and Ronald Bucca, have reached its 78th floor, the lower end of the impact zone where Flight 175 hit. [New York Times, 8/4/2002] They are just two floors below the level where, minutes later, its collapse initiates. [Federal Emergency Management Agency, 5/1/2002, pp. 2-34] Over radio, Palmer tells firefighter Joseph Leavey, “We’ve got two isolated pockets of fire. We should be able to knock it down with two lines.” [Dwyer and Flynn, 2005, pp. 206] The fact that they reached so high up the tower only comes to light almost a year later, when a tape of radio communications from 9/11 is made public (see August 4, 2002). The New York Times will report “[N]owhere on the tape is there any indication that firefighters had the slightest indication that the tower had become unstable or that it could fall.” [New York Times, 11/9/2002] Palmer’s communication appears to contradict claims that “extreme fires” contributed to the tower’s collapse. [BBC, 9/13/2001; New York Times, 10/20/2004] Ronald Bucca, a Special Forces veteran, had actually conducted his own private research into Islamic militancy following the 1993 WTC bombing. He’d even taken time, in 1996, to attend the beginning of the trial of Ramzi Yousef, a mastermind of the bombing (see September 5, 1996). [Lance, 2003, pp. 180-183, 333-334]

Entity Tags: World Trade Center, Orio Palmer, Ronald Bucca

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center, 9/11 Investigations

Fireman Mike Kehoe heads upstairs while others flee downstairs. Kehoe luckily survived the building collapses.Fireman Mike Kehoe heads upstairs while others flee downstairs. Kehoe luckily survived the building collapses. [Source: John Labriola]In the lobby of Building 7 of the WTC, EMS Division Chief John Peruggia is in discussion with Fire Department Captain Richard Rotanz and a representative from the Department of Buildings. As Peruggia later describes, “It was brought to my attention, it was believed that the structural damage that was suffered to the [Twin] Towers was quite significant and they were very confident that the building’s stability was compromised and they felt that the North Tower was in danger of a near imminent collapse.” Peruggia grabs EMT Richard Zarrillo and tells him to pass on the message “that the buildings have been compromised, we need to evacuate, they’re going to collapse.” Zarrillo heads out to the fire command post, situated in front of 3 World Financial, the American Express Building, where he relays this message to several senior firefighters. He says, “OEM says the buildings are going to collapse; we need to get out.” (OEM is the Mayor’s Office of Emergency Management, which has its headquarters in WTC 7.) Fire Chief Pete Ganci’s response is, “who the f___ told you that?” Seconds later, they hear the noise of the South Tower as it collapses. [City of New York, 10/23/2001; City of New York, 10/25/2001; City of New York, 10/25/2001; City of New York, 11/9/2001] Others also appear to have been aware of the imminent danger. Fire Chief Joseph Pfeifer, who is at the command post in the lobby of the North Tower, says, “Right before the South Tower collapsed, I noticed a lot of people just left the lobby, and I heard we had a crew of all different people, high-level people in government, everybody was gone, almost like they had information that we didn’t have.” He says some of them are moving to a new command post across the street. [City of New York, 10/23/2001; Firehouse Magazine, 4/2002; Dwyer and Flynn, 2005, pp. 214] Mayor Giuliani also says he receives a prior warning of the first collapse, while at his temporary headquarters at 75 Barclay Street (see (Before 9:59 a.m.) September 11, 2001).

Entity Tags: Richard Rotanz, Joseph Pfeifer, John Peruggia, World Trade Center, Richard (“Dick”) Cheney

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, Key Day of 9/11 Events, World Trade Center

Some witnesses near the World Trade Center feel the ground shaking just before the South Tower starts to collapse:
bullet EMT Joseph Fortis is heading across West Street, when, he says, “the ground started shaking like a train was coming.” He then looks up and sees the South Tower starting to collapse. [City of New York, 11/9/2001]
bullet Lonnie Penn, another EMT, is outside the Marriott Hotel, which is adjacent to the North Tower. He and his partner “felt the ground shake. You could see the towers sway and then it just came down.” [City of New York, 11/9/2001]
bullet Bradley Mann is at the EMS staging area on Vesey Street. He says, “Shortly before the first tower came down I remember feeling the ground shaking. I heard a terrible noise, and then debris just started flying everywhere.” [City of New York, 11/7/2001]
bullet Battalion Chief Brian O’Flaherty is walking into the lobby of the Marriott Hotel. He says, “I hear a noise. Right after that noise, you could feel the building start to shudder, tremble, under your feet.” He then hears the “terrible noise” of the South Tower collapsing. [City of New York, 1/9/2002] Witnesses will also notice the ground shaking before the North Tower collapses (see Shortly Before 10:28 a.m. September 11, 2001).

Entity Tags: Joseph Fortis, Lonnie Penn, Bradley Mann, Brian O’Flaherty

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center

People inside the World Trade Center flee down a stairway.People inside the World Trade Center flee down a stairway. [Source: Shannon Stapleton]Almost all the occupants of the South Tower who are able to evacuate the building have done so and have crossed the street to safety. Only 11 occupants who were below the impact floors are still in the building when it collapses. However, 619 building occupants in or above the impact zone have either already died or perish in the collapse, as do many emergency workers. [National Institute of Standards and Technology, 9/2005, pp. xxxix, 44] Most workers in the North Tower also leave the building before it collapses (see 10:27 a.m. September 11, 2001).

Entity Tags: World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, World Trade Center, WTC Investigation

The South Tower of the World Trade Center collapses.The South Tower of the World Trade Center collapses. [Source: Associated Press]The South Tower of the World Trade Center tilts to the southeast and then collapses. It was hit by Flight 175 at 9:03 a.m., 56 minutes earlier (see 9:03 a.m. September 11, 2001). [Washington Post, 9/12/2001; New York Times, 9/12/2001; MSNBC, 9/22/2001; USA Today, 12/20/2001; Associated Press, 8/21/2002; ABC News, 9/11/2002; National Institute of Standards and Technology, 9/2005, pp. 44] The first sign of the collapse is visible on floor 82. [National Institute of Standards and Technology, 9/2005, pp. 87] The angle of the tilt will be disputed after 9/11 (see September-November 2005), as will the time it takes the towers to fall to the ground (see September 12, 2001-September 2005). [Scientific American, 10/9/2001; Eagar and Musso, 12/2001; PBS Nova, 5/2002; National Institute of Standards and Technology, 8/30/2006]

Entity Tags: World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, Key Day of 9/11 Events, World Trade Center, 9/11 Investigations

Mayor Rudolph Giuliani will become well known for his walking press conferences in the middle of the 9/11 crisis.Mayor Rudolph Giuliani will become well known for his walking press conferences in the middle of the 9/11 crisis. [Source: Time Magazine/ Salient Stills]Between 9:25 a.m. and 9:45 a.m., one senior New York fire chief recommends to the Fire Department Chief of Department that there might be a WTC collapse in a few hours, and, therefore, fire units probably shouldn’t ascend much above the sixtieth floor (presumably this assumes the collapse would be gradual so those on lower floors would still have time to evacuate). This advice is not followed or not passed on. Apparently, no other senior fire chiefs mention or foresee the possibility of the WTC towers falling. [9/11 Commission, 5/19/2004] However, New York City Mayor Rudolph Giuliani later recounts, “I went down to the scene and we set up headquarters at 75 Barclay Street, which was right there, with the police commissioner, the fire commissioner, the head of emergency management, and we were operating out of there when we were told that the World Trade Center was going to collapse. And it did collapse before we could actually get out of the building, so we were trapped in the building for ten, 15 minutes, and finally found an exit and got out, walked north, and took a lot of people with us.” [ABC News, 9/11/2001] As can be seen by another account of similar events, this happens before the first WTC tower falls, not the second. [9/11 Commission, 5/19/2004] It is not clear who tells Giuliani to evacuate when no fire chiefs were considering the possibility of an imminent collapse. However, an EMT is also given a message around this time, warning that the towers are going to collapse. The origin of this information is apparently the Mayor’s Office of Emergency Management, so this may also have been from where Giuliani heard of the imminent collapse (see (Before 9:59 a.m.) September 11, 2001).

Entity Tags: World Trade Center, Rudolph (“Rudy”) Giuliani

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, World Trade Center, 9/11 Investigations, WTC Investigation

Numerous witnesses, including firefighters and other rescue workers, hear explosions at the start of, and during, the collapse of the south WTC tower. Some of them report hearing a single explosion:
bullet Jeff Birnbaum: “There was an explosion and the whole top leaned toward us and started coming down.” [Electrical Wholesaling, 2/1/2002]
bullet Battalion Chief John Sudnik: “[W]e heard a loud explosion or what sounded like a loud explosion and looked up and I saw Tower Two start coming down.” [City of New York, 11/7/2001]
bullet Firefighter Edward Kennedy hears “a tremendous boom, explosion… and the top of the building was coming down at us.” [City of New York, 1/17/2002]
bullet Firefighter Edward Sheehey hears “an explosion, looked up, and the building started to collapse.” [City of New York, 12/4/2001]
bullet Battalion Chief Thomas Vallebuona: “I heard ‘boom,’ an exploding sound, a real loud bang. I looked up, and I could see the Trade Center starting to come down.” [City of New York, 1/2/2002]
bullet EMT Julio Marrero: “I heard a loud bang. We looked up, and we just saw the building starting to collapse.” [City of New York, 10/25/2001]
Other witnesses report hearing multiple explosions:
bullet Journalist Pete Hamill: “We heard snapping sounds, pops, little explosions, and then the walls bulged out, and we heard a sound like an avalanche.” [New York Daily News, 9/11/2001]
bullet Police officer Sue Keane, who is an Army veteran, is located in the north WTC tower: “[I]t sounded like bombs going off. That’s when the explosions happened.… It started to get dark, then all of a sudden there was this massive explosion.” [Hagen and Carouba, 2002, pp. 65]
bullet Firefighter Keith Murphy, who is in the lobby of the North Tower: “[T]he first thing that happened, which I still think is strange to me, the lights went out.… I had heard right before the lights went out, I had heard a distant boom boom boom, sounded like three explosions.… At the time, I would have said they sounded like bombs, but it was boom boom boom and then the lights all go out.… I would say about 3, 4 seconds, all of a sudden this tremendous roar.” [City of New York, 12/5/2001]
bullet Firefighter Craig Carlsen hears “explosions coming from building two, the South Tower. It seemed like it took forever, but there were about ten explosions.… We then realized the building started to come down.” [City of New York, 1/25/2002]
bullet Firefighter Thomas Turilli, who is in the lobby of the North Tower: “[A]ll of a sudden you just heard like it almost actually that day sounded like bombs going off, like boom, boom, boom, like seven or eight, and then just a huge wind gust just came… It just seemed like a huge explosion.” [City of New York, 1/17/2002]
bullet Firefighter Stephen Viola: “[T]hat’s when the South Tower collapsed, and it sounded like a bunch of explosions. You heard like loud booms.” [City of New York, 1/10/2002]
bullet Firefighter Lance Lizzul: “[W]e heard some bangs. That made us look up, and that’s when the first Trade Center came down.” [City of New York, 12/10/2001]
bullet Paramedic Kevin Darnowski: “I heard three explosions, and then we heard like groaning and grinding, and Tower Two started to come down.” [City of New York, 11/9/2001]
However, the National Institute of Standards and Technology, which conducts a three-year study of the WTC collapses, will subsequently claim it found “no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives” (see October 26, 2005). [National Institute of Standards and Technology, 9/2005, pp. 146]

Entity Tags: Julio Marrero, Stephen Viola, John Sudnik, Craig Carlsen, Ed Kennedy, Keith Murphy, Kevin Darnowski, Pete Hamill, Edward Sheehey, World Trade Center, Lance Lizzul, Thomas Vallebuona, Sue Keane, Jeff Birnbaum, Thomas Turilli

Timeline Tags: 9/11 Timeline

Category Tags: Key Day of 9/11 Events, All Day of 9/11 Events, World Trade Center, WTC Investigation, 9/11 Investigations

Deputy Fire Commissioner Thomas Fitzpatrick.Deputy Fire Commissioner Thomas Fitzpatrick. [Source: City of New York]Numerous witnesses to the collapse of the south WTC tower think it resembles a demolition using explosives. Some initially believe this is what is occurring:
bullet Reporter John Bussey watches the collapse from the Wall Street Journal’s offices across the street from the WTC. He says, “I… looked up out of the office window to see what seemed like perfectly synchronized explosions coming from each floor, spewing glass and metal outward. One after the other, from top to bottom, with a fraction of a second between, the floors blew to pieces.” [Wall Street Journal, 9/12/2001]
bullet Deputy Fire Commissioner Thomas Fitzpatrick: “I remember seeing, it looked like sparkling around one specific layer of the building.… Then the building started to come down. My initial reaction was that this was exactly the way it looks when they show you those implosions on TV.” [City of New York, 10/1/2001]
bullet Assistant Fire Commissioner Stephen Gregory: “I saw low-level flashes. In my conversation with Lieutenant Evangelista… he questioned me and asked me if I saw low-level flashes in front of the building, and I agreed with him… I saw a flash flash flash and then it looked like the building came down.… You know like when they demolish a building, how when they blow up a building, when it falls down? That’s what I thought I saw.” [City of New York, 10/3/2001]
bullet Firefighter Richard Banaciski: “It seemed like on television they blow up these buildings. It seemed like it was going all the way around like a belt, all these explosions.” [City of New York, 12/6/2001]
bullet Firefighter Joseph Meola: “As we are looking up at the building, what I saw was, it looked like the building was blowing out on all four sides. We actually heard the pops.… You thought it was just blowing out.” [City of New York, 12/11/2001]
bullet Fire Chief Frank Cruthers: “[T]here was what appeared to be at first an explosion. It appeared at the very top, simultaneously from all four sides, materials shot out horizontally. And then there seemed to be a momentary delay before you could see the beginning of the collapse.” [City of New York, 10/31/2001]
bullet Battalion Chief Brian Dixon: “I was watching the fire… the lowest floor of fire in the South Tower actually looked like someone had planted explosives around it because the whole bottom I could see—I could see two sides of it and the other side—it just looked like that floor blew out.… I thought, geez, this looks like an explosion up there, it blew out.” [City of New York, 10/25/2001]
bullet Firefighter Timothy Burke: “Then the building popped, lower than the fire… I was going oh, my god, there is secondary device because the way the building popped I thought it was an explosion.” [City of New York, 1/22/2002]
bullet Firefighter Edward Cachia: “It actually gave at a lower floor, not the floor where the plane hit, because we originally had thought there was like an internal detonation explosives because it went in succession, boom, boom, boom, boom, and then the tower came down.” [City of New York, 12/6/2001]
bullet Firefighter Kenneth Rogers: “[T]here was an explosion in the South Tower… I kept watching. Floor after floor after floor. One floor under another after another and when it hit about the fifth floor, I figured it was a bomb, because it looked like a synchronized deliberate kind of thing.” [City of New York, 12/10/2001]
bullet Reporter Beth Fertig: “The tower went down perfectly straight, as if a demolition crew had imploded it. I wondered if it was being brought down deliberately.” [Gilbert et al., 2002, pp. 78]
bullet Paramedic Daniel Rivera: “[D]o you ever see professional demolition where they set the charges on certain floors and then you hear ‘Pop, pop, pop, pop, pop’? That’s exactly what—because I thought it was that.” [City of New York, 10/10/2001]
bullet Battalion Chief Dominick DeRubbio: “It was weird how it started to come down. It looked like it was a timed explosion.” [City of New York, 10/12/2001]
bullet The Guardian will report that police on the scene said the collapse “looked almost like a ‘planned implosion’ designed to catch bystanders watching from the street.” [Guardian, 9/12/2001]
However, the National Institute of Standards and Technology, which conducts a three-year study of the WTC collapses, will reject suggestions that the WTC towers were brought down with explosives (see August 30, 2006). CTV will assert, “[F]lashes of light that seemed to indicate bombs detonating were not explosions. They were pockets of airs being forced out of windows as the sagging floors pushed downward.” [CTV, 9/12/2006]

Entity Tags: Stephen Gregory, Edward Cachia, Dominick DeRubbio, Beth Fertig, Frank Cruthers, John Bussey, Richard Banaciski, Kenneth Rogers, World Trade Center, Joseph Meola, Timothy Burke, Brian Dixon, Daniel Rivera, Thomas Fitzpatrick

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, World Trade Center, WTC Investigation, 9/11 Investigations

The exterior wall on the south side of the World Trade Center’s North Tower apparently bows before the building collapses. The first inquiry into the collapse, by the Federal Emergency Management Agency and the American Society of Civil Engineers, states that the perimeter walls bow outward (see (9:21 a.m.-9:59 a.m. September 11, 2001)). However, a subsequent report by the National Institute of Standards and Technology states that the south wall of the North Tower bows inward. In places the wall is said to bow inward by approximately 55 inches at floor 97, and NIST interprets this bowing to mean that the floors must be sagging. NIST will find that the sagging and bowing are two of the seven major factors that led to the collapse of each tower, as the bowing walls are no longer able to support their share of the buildings’ weight, causing the buildings to tilt and the upper sections to fall. [National Institute of Standards and Technology, 9/2005, pp. 32-34, 87]

Entity Tags: World Trade Center, National Institute of Standards and Technology, Federal Emergency Management Agency

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center, 9/11 Investigations

Almost all the occupants of the North Tower who are able to evacuate the building have done so. Only 107 occupants who were below the impact floors remain in the building, while around 7,400 have escaped. However, 1,355 building occupants in or above the impact zone have either already died or perish in the collapse, as do many emergency workers. Overall, 99 percent of building occupants below the impact floors escape to safety. [National Institute of Standards and Technology, 9/2005, pp. xxxviii, 32] Most workers in the South Tower also left the building before it collapsed (see 9:58 a.m. September 11, 2001).

Entity Tags: World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center, 9/11 Investigations

Some witnesses feel the ground shaking just before the north WTC tower starts collapsing:
bullet Fire Patrolman Paul Curran is in front of the US Customs House (WTC 6), next to the North Tower. He says, “all of a sudden the ground just started shaking. It felt like a train was running under my feet.… The next thing we know, we look up and the tower is collapsing.” [City of New York, 12/18/2001]
bullet EMS Lieutenant Bradley Mann is heading toward the EMS staging area on Vesey Street. He’d felt the ground shaking prior to the first collapse (see Shortly Before 9:59 a.m. September 11, 2001). He says, “The ground shook again, and we heard another terrible noise and the next thing we knew the second tower was coming down.” [City of New York, 11/7/2001]
bullet Jay Jonas is actually inside the North Tower, on its fourth floor. Seconds before the collapse he feels “a tremendous vibration and shaking; the floor began waving.” [Providence Journal, 9/11/2002]

Entity Tags: Jay Jonas, Bradley Mann, Paul Curran

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center, 9/11 Investigations

Some witnesses to the collapse of the North Tower think it resembles a demolition using explosives:
bullet Fire Captain Dennis Tardio: “I hear an explosion and I look up. It is as if the building is being imploded, from the top floor down, one after another, boom, boom, boom.” [Smith, 2002, pp. 18]
bullet Assistant Fire Commissioner James Drury: “[P]eople in the street and myself included thought that the roar was so loud that the explosive—bombs were going off inside the building.” [City of New York, 10/16/2001]
bullet Firefighter James Curran: “I heard like every floor went chu-chu-chu. Looked back and from the pressure everything was getting blown out of the floors before it actually collapsed.” [City of New York, 12/30/2001]
bullet EMS Captain Karin Deshore: “Somewhere around the middle of the World Trade Center, there was this orange and red flash coming out. Initially it was just one flash. Then this flash just kept popping all the way around the building and that building had started to explode. The popping sound, and with each popping sound it was initially an orange and then a red flash came out of the building and then it would just go all around the building on both sides as far as I could see. These popping sounds and the explosions were getting bigger, going both up and down and then all around the building. I went inside… and I said I think we have another major explosion.” [City of New York, 11/7/2001]
The National Institute of Standards and Technology, in its report on the towers’ collapse, will reject suggestions that the Twin Towers were brought down with explosives (see August 30, 2006). [National Institute of Standards and Technology, 8/30/2006]

Entity Tags: Karin Deshore, James Drury, World Trade Center, Dennis Tardio, James Curran

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, World Trade Center, WTC Investigation, 9/11 Investigations

The North Tower collapses in a matter of seconds.The North Tower collapses in a matter of seconds. [Source: Ray Stubblebine/ Reuters/ Landov] (click image to enlarge)The North Tower of the World Trade Center tilts to the south and then collapses. Its north side was hit by Flight 11 at 8:46, 102 minutes earlier. [CNN, 9/12/2001; New York Times, 9/12/2001; MSNBC, 9/22/2001; Kim and Baum, 2002 pdf file; Associated Press, 8/21/2002; National Institute of Standards and Technology, 9/2005, pp. 33] After the antenna starts to move (see (10:28 a.m. September 11, 2001)), the next sign that the top section of the building is moving downward is on floor 98, at the top of the impact zone. [National Institute of Standards and Technology, 9/2005, pp. 22, 87] The angle of the tilt will be disputed after 9/11 (see September-November 2005), as will the time it takes the towers to fall to the ground (see September 12, 2001-September 2005). [Scientific American, 10/9/2001; Eagar and Musso, 12/2001; PBS Nova, 5/2002; National Institute of Standards and Technology, 8/30/2006] The death toll could have been much worse—an estimated 15,000 people made it out of the WTC to safety after 8:46 a.m. [St. Petersburg Times, 9/8/2002]

Entity Tags: World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, Key Day of 9/11 Events, World Trade Center, 9/11 Investigations

Fire Lieutenant Gregg HanssonFire Lieutenant Gregg Hansson [Source: BBC]Many witnesses hear explosions during the collapse of the north WTC tower. Some report hearing a single explosion:
bullet Reporter Mike Sheehan hears “another deafening explosion. I looked up and saw the top of the North Tower, the mast, begin to fall.” [Gilbert et al., 2002, pp. 126]
bullet Fire Lieutenant William Wall: “[W]e heard an explosion. We looked up and the building was coming down right on top of us.” [City of New York, 12/10/2001]
bullet Firefighter Roy Chelsen: “All of a sudden we heard this huge explosion, and that’s when the tower started coming down.” [City of New York, 1/18/2002]
bullet EMT Jason Charles: “I heard a ground level explosion and I’m like holy shit, and then you heard that twisting metal wreckage again.” [City of New York, 1/23/2002]
bullet Firefighter Kevin Murray: “When the tower started—there was a big explosion that I heard and someone screamed that it was coming down.” [City of New York, 10/9/2001]
bullet Firefighter James Ippolito: “I heard an explosion and turned around and the building was coming down.” [City of New York, 12/13/2001]
bullet Fire Lieutenant Gregg Hansson: “[A] large explosion took place. In my estimation that was the tower coming down, but at that time I did not know what that was. I thought some type of bomb had gone off.” [City of New York, 10/9/2001]
bullet Firefighter Kevin Gorman: “I heard the explosion, looked up, and saw like three floors explode, saw the antenna coming down.” [City of New York, 1/9/2002]
Others report hearing multiple explosions:
bullet EMT Gregg Brady: “I heard 3 loud explosions. I look up and the North Tower is coming down now.” [City of New York, 11/1/2001]
bullet Firefighter Richard Carletti: “I remember seeing the antenna do a little rock back and forth and I could just hear the floors pancaking. I heard it for about 30 pancakes, just boom, boom, boom, boom.” [City of New York, 1/2/2002]
bullet Fire Lieutenant Michael Cahill: “That’s when the second collapse started to come down. All kinds of noise. Boom, boom, boom, boom, boom, very loud.” [City of New York, 10/17/2001]
bullet Firefighter Sal D’Agostino is actually inside the North Tower, around its fourth floor, when the collapse occurs. He says, “It’s pancaking from the top down, and there were these huge explosions—I mean huge, gigantic explosions.” [Providence Journal, 9/11/2002; Dwyer and Flynn, 2005, pp. 241-242]
bullet Firefighter Bill Butler, who is with D’Agostino inside the tower, says, “It was like a train going two inches away from your head: bang-bang, bang-bang, bang-bang.” [Providence Journal, 9/11/2002]
bullet EMT David Timothy: “[Y]ou started hearing more explosions. I guess this is when the second tower started coming down.” [City of New York, 10/25/2001]
CTV will later assert, “When eyewitnesses claim to have heard explosions prior to the collapse, those were just the sounds of a massive building contorting and crushing anything inside.” [CTV, 9/12/2006]

Entity Tags: Jason Charles, Roy Chelsen, James Ippolito, Bill Butler, David Timothy, Kevin Gorman, Kevin Murray, Mike Sheehan, Gregg Brady, World Trade Center, Michael Cahill, William Wall, Richard Carletti, Gregg Hansson, Sal D’Agostino

Timeline Tags: 9/11 Timeline

Category Tags: Key Day of 9/11 Events, All Day of 9/11 Events, World Trade Center, WTC Investigation, 9/11 Investigations

The team studying the WTC collapses for the American Society of Civil Engineers (ASCE) and the Federal Emergency Management Agency (FEMA) will later observe that the antenna on WTC 1 began to fall before the exterior of the building: “Review of videotape recordings of the collapse taken from various angles indicates that the transmission tower on top of the structure began to move downward and laterally slightly before movement was evident at the exterior wall. This suggests that collapse began with one or more failures in the central core area of the building.” [Federal Emergency Management Agency, 5/1/2002, pp. 2-27] In a program featuring some members of the FEMA/ASCE team, the BBC will comment: “The mast was directly supported by the tower’s inner core. The way it fell suggests it was failure of the inner core that began the collapse, whereas in the South Tower it had been the outer walls.” [BBC, 3/7/2002]

Entity Tags: American Society of Civil Engineers, World Trade Center, Federal Emergency Management Agency

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center, 9/11 Investigations

According to Captain Michael Currid, the sergeant at arms for the Uniformed Fire Officers Association, some time after the collapse of the North Tower, he sees four or five fire companies trying to extinguish fires in Building 7 of the WTC. Someone from the city’s Office of Emergency Management tells him that WTC 7 is in serious danger of collapse. Currid says, “The consensus was that it was basically a lost cause and we should not lose anyone else trying to save it.” Along with some others, he goes inside WTC 7 and yells up the stairwells to the fire fighters, “Drop everything and get out!” [Murphy, 2002, pp. 175-176] However, other accounts contradict this, claiming that no attempt is made to fight the fires in WTC 7 (see (11:30 a.m.) September 11, 2001). One report later claims, “Given the limited water supply and the first strategic priority, which was to search for survivors in the rubble, FDNY did not fight the fires [in WTC 7].” [Fire Engineering, 9/2002] And a 2002 government report says, “the firefighters made the decision fairly early on not to attempt to fight the fires, due in part to the damage to WTC 7 from the collapsing towers.” [Federal Emergency Management Agency, 5/1/2002, pp. 5-21] Building 7 eventually collapses late in the afternoon of 9/11 (see (5:20 p.m.) September 11, 2001).

Entity Tags: World Trade Center, Office of Emergency Management, Michael Currid

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center

The seismic record at Palisades, NY, 34 km north of the World Trade Center.The seismic record at Palisades, NY, 34 km north of the World Trade Center. [Source: Lamont-Doherty Earth Observatory] (click image to enlarge)According to a seismographical study conducted by Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York, five distinct shocks occur at the World Trade Center site. They occur at 11:01 a.m., 11:15 a.m., 11:29 a.m., 12:07 p.m., and 12:10 p.m. According to the study, the five resulting seismic signals “may have been generated by additional collapses.” [Earth Institute at Columbia University, 11/16/2001; Kim et al., 11/20/2001 pdf file]

Entity Tags: Lamont-Doherty Earth Observatory

Category Tags: All Day of 9/11 Events, World Trade Center, WTC Investigation, 9/11 Investigations

At some point during the afternoon of 9/11, WTC leaseholder Larry Silverstein receives a phone call from the Fire Department commander, where they discuss the state of Building 7 of the WTC complex. Silverstein will discuss this call in a PBS documentary broadcast in 2002, saying that he told the commander, “You know, we’ve had such terrible loss of life, maybe the smartest thing to do is pull it. And they made that decision to pull and then we watched the building collapse.” [PBS, 9/10/2002] Some people suggest that by “pull it” Silverstein meant the deliberate demolition of the building. But a spokesman for Silverstein states that he was expressing “his view that the most important thing was to protect the safety of those firefighters, including, if necessary, to have them withdraw from the building.” [US Department of State, 9/16/2005] Yet this claim is contradicted by some accounts, according to which firefighters decided early on not to attempt fighting the fires in WTC 7 (see After 10:28 a.m. September 11, 2001)(see (11:30 a.m.) September 11, 2001). According to Haaretz, “In the afternoon of September 11, the Fire Department informed him that the smaller 7 World Trade Center building, which he owned, was going to collapse.” [Ha'aretz, 11/21/2001] Building 7 eventually collapses at around 5:20 in the afternoon (see (5:20 p.m.) September 11, 2001).

Entity Tags: Larry Silverstein

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, World Trade Center, WTC Investigation, 9/11 Investigations

The chief fire officer who has been assigned to take charge of operations at WTC Building 7 meets with his command officer, to discuss the condition of this building and the fire department’s capabilities for controlling the fires in it. A deputy fire chief who has just been in WTC 7, inspecting up to its 7th or 8th floor, reports that there was a lot of fire inside and the stairway was filling with smoke. The fire chiefs discuss the situation and identify the following conditions:
bullet WTC 7 has suffered damage caused by falling debris from the Twin Towers, and they are uncertain about its structural stability.
bullet There are large fires on at least six floors.
bullet They do not have enough equipment available for conducting operations in the building, such as hoses, standpipe kits, and handie-talkies.
bullet There is no water immediately available for fighting the fires. (However, this concern is apparently contradicted by reports that two or three fireboats are moored nearby, specifically to provide water-pumping capacity for the WTC site.)
Therefore, at around 2:30 p.m., fire officers decide to completely abandon WTC 7 and a final order is given to evacuate the site. Firefighters and other emergency workers will be withdrawn from the surrounding area (see (4:30 p.m.) September 11, 2001), and Building 7 collapses later in the afternoon (see (5:20 p.m.) September 11, 2001). [Firehouse (.com), 9/17/2001; National Institute of Standards and Technology, 9/2005, pp. 110-111]

Entity Tags: New York City Fire Department, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, Key Day of 9/11 Events, World Trade Center, 9/11 Investigations


Several small fires burn inside World Trade Center Building 7.
Several small fires burn inside World Trade Center Building 7. [Source: New York City Police Department]World Trade Center Building 7 is reported to be on fire. [CNN, 9/12/2001]

Entity Tags: World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center, 9/11 Investigations

According to numerous rescue and recovery workers, the area around WTC Building 7 is evacuated at this time. [Kansas City Star, 3/28/2004] For example:
bullet Emergency medical technician Joseph Fortis says, “They pulled us all back at the time, almost about an hour before it, because they were sure—they knew it was going to come down, but they weren’t sure.” [City of New York, 11/9/2001]
bullet Firefighter Edward Kennedy says, ” I remember [Chief Visconti] screaming about 7, No. 7, that they wanted everybody away from 7 because 7 was definitely going to collapse.” [City of New York, 1/17/2002]
bullet Firefighter Vincent Massa: “They were concerned about seven coming down, and they kept changing us, establishing a collapse zone and backing us up.” [City of New York, 12/4/2001]
bullet Firefighter Tiernach Cassidy: “[B]uilding seven was in eminent collapse. They blew the horns. They said everyone clear the area until we got that last civilian out.” [City of New York, 12/30/2001]
bullet Battalion Fire Chief John Norman: “I was detailed to make sure the collapse zone for 7 WTC had been set up and was being maintained.” [Fire Engineering, 10/2002]
Several New York Fire Department chief officers, who have surveyed Building 7, have apparently determined it is in danger of collapsing. [Fire Engineering, 9/2002] For example, Fire Chief Daniel Nigro explains their decision-making process, saying, “A number of fire officers and companies assessed the damage to the building. The appraisals indicated that the building’s integrity was in serious doubt. I issued the orders to pull back the firefighters and define the collapse zone.” [Fire Engineering, 9/2002] Fire Chief Frank Fellini says, “We were concerned that the fires on several floors and the missing steel would result in the building collapsing.” [City of New York, 12/3/2001] And Fire Captain Ray Goldbach says, “[W]e made a decision to take all of our units out of 7 World Trade Center because there was a potential for collapse.” [City of New York, 10/24/2001] However, some firefighters seem surprised at this decision. When Fire Commissioner Thomas Von Essen is making his way through hundreds of firefighters who are being held away from the WTC site, he hears complaints like, “It could take days for that building to come down,” and, “Why don’t they let us in there?” [Essen, 2002, pp. 45] When Deputy Fire Chief Nick Visconti is instructing firefighters to evacuate the area, one comment he receives is, “[O]h, that building is never coming down, that didn’t get hit by a plane, why isn’t somebody in there putting the fire out?” [Firehouse Magazine, 9/9/2002]

Entity Tags: Nick Visconti, Daniel Nigro, Joseph Fortis, John Norman, World Trade Center, Ray Goldbach, Thomas Von Essen, Edward M. (“Ted”) Kennedy, Vincent Massa, Tiernach Cassidy, Frank Fellini

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, Key Day of 9/11 Events, World Trade Center, 9/11 Investigations

Mark Jacobson, a reporter for New York Magazine, later recounts an encounter he has about this time. Walking through the ruins of the World Trade Center complex, he sits down next to a weary and dust covered firefighter. The firefighter points to WTC Building 7, perhaps 400 yards away, and says, “That building is coming down.” Jacobson asks when and the firefighter responds, “Tonight. Maybe tomorrow morning.” Jacobson watches as the building collapses about five minutes later. [New York Magazine, 3/20/2006]

Entity Tags: Mark Jacobson

Timeline Tags: 9/11 Timeline

Category Tags: All Day of 9/11 Events, WTC Investigation, World Trade Center, 9/11 Investigations

A four-image progression of photos showing World Trade Center Building 7 collapsing down into its footprint.A four-image progression of photos showing World Trade Center Building 7 collapsing down into its footprint. [Source: unknown] (click image to enlarge)Building 7 of the World Trade Center complex, a 47-story tower, collapses. No one is killed. [CNN, 9/12/2001; Washington Post, 9/12/2001; MSNBC, 9/22/2001; Associated Press, 8/21/2002] It collapses in 6.6 seconds, which is just 0.6 of a second longer than it would have taken a free-falling object dropped from its roof to hit the ground. [Deseret Morning News, 11/10/2005] Many questions will arise over the cause of its collapse in the coming months and years. Building 7, which was not hit by an airplane, is the first modern, steel-reinforced high-rise to collapse because of fire. [Chicago Tribune, 11/29/2001; Stanford Report, 12/5/2001; New York Times, 3/2/2002] Some will later suggest that the diesel fuel stored in several tanks on the premises may have contributed to the building’s collapse. The building contained a 6,000-gallon tank between its first and second floors and another four tanks, holding as much as 36,000 gallons, below ground level. There were also three smaller tanks on higher floors. [Chicago Tribune, 11/29/2001; New York Times, 3/2/2002; New York Observer, 3/25/2002; Federal Emergency Management Agency, 5/1/2002, pp. 1-17] However, the cause of the collapse is uncertain. A 2002 government report will conclude: “The specifics of the fires in WTC 7 and how they caused the building to collapse remain unknown at this time. Although the total diesel fuel on the premises contained massive potential energy, the best hypothesis has only a low probability of occurrence.” [Federal Emergency Management Agency, 5/1/2002, pp. 1-17] Some reports indicate that the building may have been deliberately destroyed. Shortly after the collapse, CBS News anchor Dan Rather comments that the collapse is “reminiscent of… when a building was deliberately destroyed by well-placed dynamite to knock it down.” [CBS News, 9/11/2001] And moments after the collapse, MSNBC’s Brian Williams joins David Restuccio, an FDNY lieutenant, by phone to ask him about the collapse. “You guys knew this was coming all day?” asks Williams. Restuccio replies: “We had heard reports that the building was unstable, and that it would eventually need to come down on its own, or it would be taken down. I would imagine it came down on its own.” Restuccio does not explain what he means by “it would be taken down.” [MSNBC, 9/11/2001]

Entity Tags: Dan Rather, World Trade Center, David Restuccio

Timeline Tags: 9/11 Timeline

Category Tags: Key Day of 9/11 Events, All Day of 9/11 Events, World Trade Center, WTC Investigation, 9/11 Investigations

Michael Burton.Michael Burton. [Source: PBS]Following the World Trade Center collapses, a decision is made to quickly transport the remaining structural steel to scrap yards, to be shipped abroad and melted down for reuse. Consequently, virtually all of it is disposed of before investigators trying to assess why the WTC collapsed can examine it. Michael Burton and other officials at the Department of Design and Construction—the New York City agency overseeing the cleanup operation (see (September 11, 2001-May 2002))—are responsible for making this decision. Burton clears it with Richard Tomasetti of Thornton-Tomasetti Engineers, the prime consultant on the cleanup job. However, referring to the subsequent WTC investigation by the National Institute of Standards and Technology (see August 21, 2002), Tomasetti will later admit that had he known the direction that investigations into the collapses would take, he would have taken a different stand. [Langewiesche, 2002, pp. 30; Glanz and Lipton, 2004, pp. 330 and 396] Authors and New York Times reporters James Glanz and Eric Lipton write that Michael Burton, “who had become the effective czar for the cleanup job, had made it clear that he cared very little about engineering subtleties like the question of why the towers first stood, then collapsed on September 11. ‘We know why they fell,’ he said. ‘Because they flew two planes into the towers.’ But he was deeply immersed in the details of hauling steel out of the debris pile.” [Glanz and Lipton, 2004, pp. 299] Much of the WTC steel will be shipped to India, China, and other Asian countries for recycling (see September 12-October 2001).

Entity Tags: New York City Department of Design and Construction, World Trade Center, Michael Burton, Richard Tomasetti

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

W. Gene Corley.W. Gene Corley. [Source: ASCE]The Federal Emergency Management Agency (FEMA) and its contractor, Greenhorne and O’Mara, Inc., from Greenbelt, Maryland, begin putting together a Building Performance Assessment Team (BPAT), to conduct a formal analysis of the World Trade Center collapses, and produce a report of its findings. FEMA routinely deploys such teams following disasters, like floods or hurricanes. The 23-member BPAT team set up at the WTC collapse site is assembled by the American Society of Civil Engineers (ASCE), and headed by Dr. W. Gene Corley of Construction Technologies Laboratories in Skokie, Illinois. Corley was previously the principal investigator for FEMA’s study of the Murrah Building, in Oklahoma City in 1995. [New Yorker, 11/12/2001] BPAT team members are based nationwide and have to communicate with each other mostly by phone, as they continue with their regular jobs. While some of them are being paid for their efforts, others are working on the investigation voluntarily. They are told not to speak with reporters, under threat of dismissal from the team, supposedly because of the delicacy of the subject with which they are dealing. The BPAT team receives $600,000 of funding from FEMA, plus approximately $500,000 in ASCE in-kind contributions. [New York Times, 12/25/2001; Associated Press, 1/14/2002; US Congress, 3/6/2002] The team will have great difficulty accessing the collapse site and evidence they want to see (see March 6, 2002). They will be unable to get FEMA to obtain such basic data as detailed blueprints of the WTC buildings. FEMA will also refuse to allow them to make appeals to the public for photos and videos of the towers that might aid their investigation. Bureaucratic restrictions will often prevent them from making forensic inspections at Ground Zero, interviewing witnesses, or getting important evidence, like recorded distress calls from people who were trapped in the towers. [Glanz and Lipton, 2004, pp. 330] The end product of their investigation is the FEMA World Trade Center Building Performance Study, released in May 2002 (see May 1, 2002).

Entity Tags: World Trade Center, W. Gene Corley, American Society of Civil Engineers, Federal Emergency Management Agency, Greenhorne and O’Mara, Inc.

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

John McColeJohn McCole [Source: Robson Books]Some gruesome remains are discovered in the World Trade Center ruins:
bullet Investigators find a pair of severed hands bound together with plastic handcuffs on a nearby building. They are believed to have belonged to a flight attendant. [Newsday, 9/15/2001]
bullet Honorary firefighter Michael Bellone and two other recovery workers discover the body of an attendant from American Airlines Flight 11. Reportedly, the men’s digging efforts reveal “a blue skirt, then one side of a body, and finally a pair of wings still attached to the lapel of a woman’s jacket.” [Swanson, 2003, pp. 140; Daily Standard (Grand Lake), 9/11/2006] Other reports describe the discovery of the body of a flight attendant with her hands bound. Presumably they are referring to the same remains. [Guardian, 9/13/2001; New York Times, 9/15/2001]
bullet There are reports of whole rows of seats with passengers in them being found, as well as much of the cockpit of one of the planes, complete with the body of a suspected hijacker. Police cannot confirm these reports. [Ananova, 9/13/2001; Guardian, 9/13/2001; New York Times, 9/15/2001]
bullet Fire Lieutenant John McCole sees a body bag with a tag on it saying, “Possible Perp—pilot.” McCole later comments, “I found it pretty amazing that someone’s body could remain so intact after crashing through a skyscraper into the middle of an inferno.” [McCole, 2002, pp. 57] Yet, contradicting the claim that a hijacker’s body was found, only in February 2003 are the remains of two hijackers identified (see Late February 2003).
While all of these bodies and plane parts are supposedly found, it will be claimed that none of the four black boxes for the two aircraft that hit the WTC are ever found. A National Transportation Safety Board spokesperson later says: “It’s extremely rare that we don’t get the recorders back. I can’t recall another domestic case in which we did not recover the recorders.” [CBS News, 2/23/2002] The black boxes are considered “nearly indestructible,” are placed in the safest parts of the aircraft, and are designed to survive impacts much greater than the WTC impact. They can withstand heat of up to 2,000 degrees Fahrenheit for one hour, and can withstand an impact of an incredible 3,400 G’s. [ABC News, 9/17/2001] However, in 2004, it will be reported that some of the black boxes are found in the weeks after 9/11, but their discovery is kept secret (see October 2001).

Entity Tags: World Trade Center, Mike Bellone, National Transportation Safety Board, John McCole

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, FBI 9/11 Investigation, 9/11 Investigations

A chunk of hot metal being removed from the North Tower rubble about eight weeks after 9/11.
A chunk of hot metal being removed from the North Tower rubble about eight weeks after 9/11. [Source: Frank Silecchia]In the weeks and months after 9/11, numerous individuals report seeing molten metal in the remains of the World Trade Center:
bullet Ken Holden, who is involved with the organizing of demolition, excavation and debris removal operations at Ground Zero, later will tell the 9/11 Commission, “Underground, it was still so hot that molten metal dripped down the sides of the wall from [WTC] Building 6.” [9/11 Commission, 4/1/2003]
bullet William Langewiesche, the only journalist to have unrestricted access to Ground Zero during the cleanup operation, describes, “in the early days, the streams of molten metal that leaked from the hot cores and flowed down broken walls inside the foundation hole.” [Langewiesche, 2002, pp. 32]
bullet Leslie Robertson, one of the structural engineers responsible for the design of the WTC, describes fires still burning and molten steel still running 21 days after the attacks. [SEAU News, 10/2001 pdf file]
bullet Alison Geyh, who heads a team of scientists studying the potential health effects of 9/11, reports: “Fires are still actively burning and the smoke is very intense. In some pockets now being uncovered, they are finding molten steel.” [Johns Hopkins Public Health Magazine, 2001]
bullet Ron Burger, a public health advisor who arrives at Ground Zero on September 12, says that “feeling the heat” and “seeing the molten steel” there reminds him of a volcano. [National Environmental Health Association, 9/2003, pp. 40 pdf file]
bullet Paramedic Lee Turner arrives at the World Trade Center site on September 12 as a member of a federal urban search and rescue squad. While at Ground Zero, he goes “down crumpled stairwells to the subway, five levels below ground.” There he reportedly sees, “in the darkness a distant, pinkish glow—molten metal dripping from a beam.” [US News and World Report, 9/12/2002]
bullet According to a member of New York Air National Guard’s 109th Air Wing, who is at Ground Zero from September 22 to October 6: “One fireman told us that there was still molten steel at the heart of the towers’ remains. Firemen sprayed water to cool the debris down but the heat remained intense enough at the surface to melt their boots.” [National Guard Magazine, 12/2001]
bullet New York firefighters recall “heat so intense they encountered rivers of molten steel.” [New York Post, 3/3/2004]
bullet As late as five months after the attacks, in February 2002, firefighter Joe O’Toole sees a steel beam being lifted from deep underground at Ground Zero, which, he says, “was dripping from the molten steel.” [Knight Ridder, 5/29/2002]
Steven E. Jones, a physics professor from Utah, later will claim this molten metal is “direct evidence for the use of high-temperature explosives, such as thermite,” used to deliberately bring down the WTC towers. [MSNBC, 11/16/2005] He will say that without explosives, a falling building would have “insufficient directed energy to result in melting of large quantities of metal.” [Deseret Morning News, 11/10/2005] There is no mention whatsoever of the molten metal in the official reports by FEMA, NIST, or the 9/11 Commission. [Federal Emergency Management Agency, 5/1/2002; 9/11 Commission, 7/24/2004; National Institute of Standards and Technology, 9/2005] But Dr. Frank Gayle, who leads the steel forensics aspects of NIST’s investigation of the WTC collapses, is quoted as saying: “Your gut reaction would be the jet fuel is what made the fire so very intense, a lot of people figured that’s what melted the steel. Indeed it didn’t, the steel did not melt.” [ABC News 7 (New York), 2/7/2004] As well as the reports of molten metal, data collected by NASA in the days after 9/11 finds dozens of “hot spots” (some over 1,300 degrees) at Ground Zero (see September 16-23, 2001).

Entity Tags: Ken Holden, Frank Gayle, Lee Turner, Leslie Robertson, Ron Burger, Steven E. Jones, Alison Geyh, World Trade Center, William Langewiesche, Joe O’Toole

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Following the attacks, there is no agreement on the speed with which the Twin Towers of the World Trade Center collapsed on 9/11 (see 9:59 a.m. September 11, 2001 and 10:28 a.m. September 11, 2001). The 9/11 Commission says that the South Tower collapsed in “ten seconds” and the National Institute of Standards and Technology says that tops of the buildings came down “essentially in free fall.” [9/11 Commission, 7/24/2004, pp. 305; National Institute of Standards and Technology, 9/2005, pp. 146] In the dispute over the reason for the WTC’s collapse after 9/11, it is claimed that, if the towers fell in ten seconds, then this is evidence they were destroyed by explosives. For example, David Ray Griffin, a theologian and outspoken critic of commission’s report, writes, “For a 1,300-foot building, however, ten seconds is almost free-fall speed. But if each floor produced just a little resistance, so that breaking through each one took half a second, the collapse of all those floors—80 or 95 of them—would have taken 40 to 47 seconds. Can we really believe that the upper part of the buildings encountered virtually no resistance from the lower part?” [Griffin, 2004, pp. 16] But according to Canadian scientist Frank Greening, who studies the Twin Towers’ collapse, the freefall time would be about 9.6 seconds, and he calculates that it takes longer for the buildings to fall—twelve to thirteen and a half seconds—and states this does not indicate that explosives were used. [Canadian Broadcasting Corporation, 8/25/2005]

Entity Tags: World Trade Center, Frank Greening, National Institute of Standards and Technology, David Ray Griffin, 9/11 Commission

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Steel beams from the WTC were already being removed and recycled on September 20, 2001.Steel beams from the WTC were already being removed and recycled on September 20, 2001. [Source: Associated Press]In the month following 9/11, a significant amount of the steel debris from the WTC collapses is removed from the rubble pile, cut into smaller sections, and either melted at a recycling plant or shipped out of the US. [US Congress, 3/6/2002] Each of the Twin Towers contained 78,000 tons of recyclable steel. Much of this is shipped to India, China, and other Asian countries, where it will be melted down and reprocessed into new steel products. Asian companies are able to purchase the steel for just $120 per ton, compared, for example, to a usual average price of $150 per ton in China. Industry officials estimate that selling off the steel and other metals from the WTC for recycling could net a few tens of million dollars. [New York Times, 10/9/2001; Reuters, 1/21/2002; Reuters, 1/22/2002; Eastday, 1/24/2002; CorpWatch, 2/6/2002] 9/11 victims’ families and some engineers are angered at the decision to quickly discard the steel, believing it should be examined to help determine how the towers collapsed. A respected fire fighting trade magazine comments, “We are literally treating the steel removed from the site like garbage, not like crucial fire scene evidence.” [Fire Engineering, 1/2002] Rep. Joseph Crowley (D-NY) will later call the loss of this evidence “borderline criminal.” By March 2002, 150 pieces of steel from the WTC debris will have been identified by engineers for use in future investigations (see March 6, 2002). [Federal Emergency Management Agency, 5/1/2002, pp. D-13] A study by the National Institute of Standards and Technology (NIST), which commences in August 2002 [National Institute of Standards and Technology, 8/21/2002; Associated Press, 8/21/2002] , will have 236 pieces of recovered steel available to it. Of these, 229 pieces are from WTC 1 and 2, representing “roughly 0.25 percent to 0.5 percent of the 200,000 tons of structural steel used in the construction of the two towers.” [National Institute of Standards and Technology, 9/2005, pp. 85 pdf file] New York Mayor Mike Bloomberg defends the decision to quickly get rid of the WTC steel, saying, “If you want to take a look at the construction methods and the design, that’s in this day and age what computers do. Just looking at a piece of metal generally doesn’t tell you anything.” Officials in the mayor’s office decline to reply to requests by the New York Times regarding who decided to have the steel recycled. [New York Times, 12/25/2001; Eastday, 1/24/2002]

Entity Tags: Joseph Crowley, World Trade Center, Michael R. Bloomberg

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Ronald Hamburger, a member of NIST’s WTC team and advocate of the ‘piledriver’ theory.Ronald Hamburger, a member of NIST’s WTC team and advocate of the ‘piledriver’ theory. [Source: National Council of Structural Engineers' Associations]After 9/11, the scientists investigating the WTC collapse give very different figures for the buildings’ weight. Some sources say that each building weighed 500,000 tons. For example, MIT professor Thomas Eager writes, “The total weight of each tower was about 500,000 t.” [Scientific American, 10/9/2001; Eagar and Musso, 12/2001; Frank Greening, 2/16/2006, pp. 23 pdf file; PBS, 8/2006] However, the National Institute of Standards and Technology (NIST) states that the buildings weighed only 250,000 tons each. [National Institute of Standards and Technology, 9/2005, pp. 32] One theory explaining the building’s total collapse is that the upper section acts as a “piledriver” and smashes through the floors below it. [BBC, 9/13/2001; Stanford Report, 12/5/2001] The heavier the upper block above the impact zone, the more likely it is to be able to destroy the other floors as it falls.

Entity Tags: World Trade Center, Thomas Eager, National Institute of Standards and Technology

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Workers involved in the cleanup at Ground Zero find that much of the World Trade Center towers and their contents have been pulverized to dust. Charlie Vitchers, a construction superintendent who oversees the operation, says, “Apart from recoveries, we didn’t find one thing. Nothing. Not even a file cabinet.… As we were working on the pile, people were saying, ‘We’re not finding anything.’” He adds, “We weren’t going to find anything that was made out of wood. But you think we would have found a computer.… We found cell phones. We found shoes. But with regard to furniture, nothing, not a thing, not a desk, not a wall panel.… [F]or the most part there was nothing in the pile of debris that was recognizable.” Crane operator Bobby Gray says, “I don’t remember seeing carpeting or furniture. You’d think a metal file cabinet would make it, but I don’t remember seeing any, or phones, computers, none of that stuff. There were areas where there were no fires, which is not to say that they didn’t experience tremendous heat anyway. But even in areas that never burned we didn’t find anything.” He comments, “It was just so hard to comprehend that everything could have been pulverized to that extent. How do you pulverize carpet or filing cabinets?” [Stout, Vitchers, and Gray, 2006, pp. 143-144] According to Greg Meeker of the US Geological Survey, “Six million sq ft of masonry, 5 million sq ft of painted surfaces, 7 million sq ft of flooring, 600,000 sq ft of window glass, 200 elevators, and everything inside came down as dust” when the towers collapsed. “The only thing that didn’t get pulverized was the WTC towers’ 200,000 tons of structural steel.” [Chemical and Engineering News, 10/20/2003] Some people will later claim that this complete pulverization of the WTC is evidence of the towers having been brought down deliberately, using explosives. [Griffin, 2004, pp. 26; Griffin and Scott, 2006, pp. 46-47]

Entity Tags: Gregory Meeker, World Trade Center, Bobby Gray, Charlie Vitchers

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Kenneth Holden.Kenneth Holden. [Source: Public domain]The New York City agency that oversees the Ground Zero cleanup operation following the 9/11 attacks is the Department of Design and Construction (DDC). [Glanz and Lipton, 2004, pp. 299] This obscure 1,300-man bureaucracy is normally responsible for overseeing municipal construction contracts, such as street repairs and jails. Its two top officials are Kenneth Holden and his lieutenant, Michael Burton. [Langewiesche, 2002, pp. 9] Burton is in lower Manhattan the morning of 9/11, instead of in his office in Queens, for a meeting at City Hall, just a few blocks away from the World Trade Center. [Engineering News-Record, 4/22/2002] That afternoon, he meets Holden and together they begin organizing the cleanup operation. By 5:30 p.m., the group of workers they have assembled gains permission to explore the WTC ruins. Under Burton’s direction, the team of “unbuilders” subsequently undertakes what journalist William Langewiesche describes as “the most aggressive possible schedule of demolition and debris removal.” Yet this appears to go against established procedures. On previous occasions the standard emergency response to natural or man-made disasters in the US, such as the 1995 Oklahoma City bombing, was to rapidly nationalize efforts on the ground, under the direction of FEMA and the Army Corps of Engineers. [Langewiesche, 2002, pp. 66, 90, 94, 146] New York’s official emergency plans, which were written before 9/11, in fact require the Department of Sanitation to remove debris after a building collapse. A mid-level official who was involved in writing the latest plans mentions a week after 9/11 that she doesn’t even know quite what the DDC is. DDC’s only previous experiences of dealing with emergencies are a sinking EMS station in Brooklyn, caused by a water leak, and a structural failure at Yankee Stadium. According to Langewiesche, there is no specific moment when Holden and Burton are placed in charge of the Ground Zero cleanup effort. “Rather, there was a shift of power in their direction that was never quite formalized and, indeed, was unjustified by bureaucratic logic or political considerations.” Reportedly, at some point, Mayor Rudolph Giuliani made a “back-room decision to scrap the organization charts, to finesse the city’s own Office of Emergency Management (OEM), and to allow the DDC to proceed.” [Langewiesche, 2002, pp. 66, 88 and 118; Engineering News-Record, 4/22/2002] The Ground Zero cleanup operation officially ends in May 2002. [CBS News, 5/16/2002; New York Times, 5/29/2002]

Entity Tags: Rudolph (“Rudy”) Giuliani, Michael Burton, Ken Holden, World Trade Center, New York City Department of Design and Construction

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Lidar map of Ground Zero.Lidar map of Ground Zero. [Source: EarthData/Library of Congress]EarthData, a geospatial imaging company, is tasked by New York authorities with producing maps of Ground Zero using “light detection and ranging” or “lidar” technology. Lidar is similar to radar but uses a laser light instead of radio waves to measure elevation. This information is then merged with GPS data to produce a color-coded map. EarthData will make daily flights over the area for several months starting mid-September to provide rescuers and removal workers with up-to-date representations of Ground Zero. [New York Times, 9/23/2001; New York Times, 10/2/2001] The Library of Congress will later present some of the maps in an online exhibit which also includes aerial photography and video fly-through simulations of the World Trade Center, both before and after the attacks. [www.loc.gov, 2004]

Entity Tags: EarthData International, Inc.

Category Tags: WTC Investigation, 9/11 Investigations

Thermal hot spots detected by satellite on September 16, 2001. Red and orange indicate the hottest locations. The World Trade Center Twin Towers footprint is in the lower center and the center of World Trade Center Building 7 is in the upper right.
Thermal hot spots detected by satellite on September 16, 2001. Red and orange indicate the hottest locations. The World Trade Center Twin Towers footprint is in the lower center and the center of World Trade Center Building 7 is in the upper right. [Source: USGS]In response to requests from the Environmental Protection Agency, through the US Geological Survey, NASA flies a plane over the site of the WTC complex, equipped with a remote sensing instrument called AVIRIS. AVIRIS is able to remotely record the near-infrared signature of heat. Analysis of the data it collects indicates temperatures at Ground Zero of above 800 degrees Fahrenheit, with some areas above 1,300 degrees. On September 16, dozens of “hot spots” are seen, but by September 23, only four or five remain. [US Geological Survey, 11/27/2001; US Geological Survey, 10/2002 pdf file] Robert Shaler, the scientist who leads the forensic examination by the New York City medical examiner’s office to identify 9/11 victims, later will state that the “DNA in the bodies” of WTC victims “was in pretty bad shape. These bones were exposed to extreme temperatures.” [US News and World Report, 12/5/2005] Don Carson, a hazardous materials expert, later will say, “There are pieces of steel being pulled out [of the WTC rubble] that are still cherry red. It’s like the charcoal that you put in your grill.… You light it and it stays hot.” [New York Daily News, 11/1/2001] And Dr. Jonathan Barnett, a member of FEMA’s WTC investigation team, will describe steel members in the debris pile that appear to have been partly evaporated in extremely high temperatures. [New York Times, 11/29/2001] Despite the WTC rubble being pumped with an almost constant jet of water, eventually totaling thousands of gallons, almost 12 weeks after 9/11 at least one fire is still burning, making it the longest-burning structural fire in history. [New Scientist, 12/3/2001; CBS News, 12/19/2001] As well as the hot spots, numerous witnesses describe molten metal being found at Ground Zero (see September 12, 2001-February 2002).

Entity Tags: Robert Shaler, Jonathan Barnett, National Aeronautics and Space Administration, Don Carson

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Dr. Abolhassan Astaneh-Asl examines steel from the World Trade Center.Dr. Abolhassan Astaneh-Asl examines steel from the World Trade Center. [Source: University of California, Berkeley]An engineer investigating the remains of the World Trade Center sees melted girders and other evidence that the towers experienced extreme temperatures on 9/11. Dr. Abolhassan Astaneh-Asl is a professor of civil and environmental engineering at the University of California, Berkeley. He specializes in studying structural damage done by earthquakes and terrorist bombings. [Chronicle of Higher Education, 12/7/2001; CBS News, 3/11/2002] He arrives in New York on September 19 to conduct a two-week scientific reconnaissance of the collapsed towers, hoping to gain an understanding of how they had come down. His project is one of eight financed by the National Science Foundation to study the WTC disaster. [New York Times, 10/2/2001; Berkeleyan, 10/3/2001; US Congress. House. Committee on Science, 3/6/2002] He examines numerous pieces of steel taken from Ground Zero. [Chronicle of Higher Education, 12/7/2001] Astaneh-Asl will describe the WTC as “the best-designed building I have ever seen.” [San Francisco Chronicle, 10/22/2001] Yet he notices unusual warping and other damage in its remaining steel:
bullet At a recycling center in New Jersey, he sees 10-ton steel beams from the towers that look “like giant sticks of twisted licorice.” [Chronicle of Higher Education, 12/7/2001] He shows the San Francisco Chronicle a “banana-shaped, rust-colored piece of steel” that has “twisted like toffee during the terrorist attack.” [San Francisco Chronicle, 10/22/2001]
bullet He later recalls, “I saw melting of girders in [the] World Trade Center.” [PBS, 5/10/2007]
bullet He notes that steel has bent at several connection points that had joined the floors of the WTC to the vertical columns. He describes the connections as being smoothly warped, saying, “If you remember the Salvador Dali paintings with the clocks that are kind of melted—it’s kind of like that.” He adds, “That could only happen if you get steel yellow hot or white hot—perhaps around 2,000 degrees.” [Chronicle of Higher Education, 12/7/2001]
bullet Astaneh-Asl says that steel flanges have been reduced “from an inch thick to paper thin.” [Berkeleyan, 10/3/2001]
bullet He finds a foot-long twisted shard of steel that is “like a piece of bread, but it was high-strength steel.” He comments, “I haven’t seen anything like this [before].” [Berkeley Daily Planet, 10/20/2001]
bullet He finds “severely scorched [steel] members from 40 or so floors below the points of impact [by the planes].” He believes this is the result of the planes having destroyed the elevator walls, thereby allowing burning jet fuel to pour down into the building, igniting fires hundreds of feet below the impact floors. [CBS News, 3/12/2002]
bullet He says that, in some places, the fireproofing used to protect the WTC steel has “melted into a glassy residue.” [New York Times, 10/2/2001]
bullet Astaneh-Asl sees a charred I-beam from WTC Building 7, which collapsed late in the afternoon of 9/11. “The beam, so named because its cross-section looks like a capital I, had clearly endured searing temperatures. Parts of the flat top of the I, once five-eighths of an inch thick, had vaporized.” [New York Times, 10/2/2001]
Other individuals will report seeing molten metal in the remains of the World Trade Center in the weeks and months after 9/11 (see September 12, 2001-February 2002), and data collected by NASA reveals dozens of “hot spots” (some over 1,300 degrees Fahrenheit) at Ground Zero (see September 16-23, 2001). But Thomas Eagar—an engineering professor at the Massachusetts Institute of Technology—later comments that the “temperature of the fire at the WTC [on 9/11] was not unusual, and it was most definitely not capable of melting steel.” [Eagar and Musso, 12/2001] Yet Astaneh-Asl will later put forward the “tentative” conclusion, “The collapse of the [Twin Towers] was most likely due to the intense fire initiated by the jet fuel of the planes and continued due to burning of the building contents.” [Astaneh-Asl, 11/30/2003 pdf file] Astaneh-Asl is a member of the team assembled by the American Society of Civil Engineers to investigate the World Trade Center site after 9/11 (see September 12, 2001), though he will resign from this because he disagrees with its decision to keep findings secret until the initial inquiry has been completed. [New York Times, 10/2/2001; Associated Press, 9/6/2002]

Entity Tags: World Trade Center, Thomas Eagar, Abolhassan Astaneh-Asl

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

New York City Mayor Rudolph Giuliani bans any photography or video recording at the Ground Zero wreckage zone of the WTC collapses unless authorized by the police commissioner, claiming this is because it is a crime scene. Signs warn the public of a class-B misdemeanor and police keep the press away from the site. [Associated Press, 9/26/2001] It is unclear how long the ban lasts, but it seems to continue into 2002 (see From September 25, 2001 to Summer 2002).

Entity Tags: Rudolph (“Rudy”) Giuliani

Category Tags: WTC Investigation, 9/11 Investigations

After unauthorized photography at Ground Zero is banned by New York City authorities on September 25, 2001 (see September 25, 2001), independent or press-affiliated photographers find it difficult to enter the secured perimeter. Only one professional photographer, Gary M. Suson, obtains official permission to work at the site. He will publish his work in the book Requiem: Images of Ground Zero. [Suson, 2002; New York Times, 5/28/2002] Photographs taken by New York Police officers will be gathered in the book Above Hallowed Ground: A Photographic Record of September 11, 2001. [Department, 2002] Joel Meyerowitz, a renowned independent photographer, is unable to obtain permission but manages to insert himself into “the forbidden city”. Wily and persistent, Meyerowitz makes friends among some police officers, acquires a hard hat and some gloves to look inconspicuous, and even forges a work permit on his home computer, and succeeds in photographing Ground Zero over a period of nine months. He will later publish this invaluable record in the 2006 book Aftermath: World Trade Center Archive. [Meyerowitz, 2006; Observer, 8/27/2006; New York Times, 9/3/2006]

Entity Tags: Joel Meyerowitz, Gary M. Suson

Category Tags: 9/11 Investigations, WTC Investigation

Two weeks after 9/11, engineers Pablo Lopez and Andrew Pontecorvo are walking in the B2 basement level at the ruins of the World Trade Center, towards where the North Tower stood. They discover a “solid, rocklike mass where the basement levels of the tower had been,” and see “the recognizable traces of twenty floors, very much like geologic strata revealed by a road cut, compressed into a ten-foot vertical span. In one place, the steel decks of half a dozen floors protruded like tattered wallpaper, so close together that they were almost touching where they were bent downward at the edge. Nothing between the decks was recognizable except as a rocky, rusty mishmash. In a few places what might have been carbonized, compressed stacks of paper stuck out edgewise like graphite deposits.” As New York Times reporters James Glanz and Eric Lipton describe, Lopez and Pontecorvo have found “where the vanished floors [of the tower] had gone. They had not just fallen straight down. The forces had been so great and the floors so light that they had simply folded up like deflated balloons.” Furthermore, they see the massive core columns of the tower, which are over two feet wide and made of four-inch thick steel plate, appearing to have suffered “a compound fracture: the upper sections looked as if they had been kicked, with incalculable fury, about a foot south of the sections they were resting on.” Lopez remarks, “Can you imagine the force?” [Glanz and Lipton, 2004, pp. 292-293] At some later time, ironworker Danny Doyle, who is also working at Ground Zero, finds that floors of the South Tower have been compressed into a formation like what happened with the North Tower’s. He discovers “a distinct mound of debris set into the pile, about six feet high, with strands of wire and pieces of rebar sticking out. It looked like layers of sediment that had turned into rock and been lifted up on some mountainside.… Here were ten stories of the South Tower, compacted into an area of about six feet.” [Glanz and Lipton, 2004, pp. 310]

Entity Tags: Danny Doyle, Pablo Lopez, Andrew Pontecorvo, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Commission

The New York Police and FBI are investigating the theft of over 250 tons of steel from the remains of the collapsed WTC towers. Apparently, the steel was hauled away by trucks involved in the official clear-up operation (see September 12-October 2001), but instead of being taken to Fresh Kills—the FBI-controlled dump on Staten Island where it was intended to go—the steel was driven to three independently-owned scrapyards, two in New Jersey and one on Long Island. The London Telegraph says the scrap metal value of the stolen steel would have been roughly $17,500. Investigators believe the theft was organized by one of New York’s Mafia families. [Daily Telegraph, 9/29/2001] Consequently, on November 26, 2001, the city initiates use of an in-vehicle Global Positioning System (GPS), to monitor the locations of nearly 200 trucks removing steel from the WTC collapse site, at a cost of $1,000 per unit. This system sends out alerts if any truck travels off course or arrives late at its destination. One driver involved with the clear-up operation is subsequently dismissed simply for taking an extended lunch break. [Access Control and Security Systems, 7/2002]

Entity Tags: World Trade Center, New York City Police Department, Federal Bureau of Investigation

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

A sample of WTC steel eroded and corroded due to eutectic formations.A sample of WTC steel eroded and corroded due to eutectic formations. [Source: FEMA]The Journal of the Minerals, Metals and Materials Society (JOM) reports that the examination of a beam from the remains of WTC Building 7—which collapsed late in the afternoon of 9/11 (see (5:20 p.m.) September 11, 2001)—has revealed “unexpected erosion” of the steel. The article states: “The formation of the eutectic mixture of iron oxide and iron sulfide lowers the temperature at which liquid can form in this steel. This strongly suggests that the temperatures in this region of the steel beam approached around 1,000°C, forming the eutectic liquid by a process similar to making a ‘blacksmith’s weld’ in a hand forge.” [Barnett, Biederman, and Sisson, 12/2001] The New York Times will call this “perhaps the deepest mystery uncovered in the investigation.” [New York Times, 2/2/2002] FEMA’s World Trade Center Building Performance Study, released in May 2002 (see May 1, 2002), will add that the same “unusual erosion patterns” have been observed in a sample of the remaining structural steel from one of the Twin Towers. It will state, “This sulfur-rich liquid penetrated preferentially down grain boundaries of the steel, severely weakening the beam and making it susceptible to erosion.” FEMA is unable to explain this phenomenon, saying, “The severe corrosion and subsequent erosion… are a very unusual event. No clear explanation for the source of the sulfur has been identified.… It is possible that this is the result of long-term heating in the ground following the collapse of the buildings. It is also possible that the phenomenon started prior to collapse and accelerated the weakening of the steel structure.” [Federal Emergency Management Agency, 5/1/2002, pp. C-1 - C-13] Despite FEMA’s call for further research, the National Institute of Standards and Technology (NIST) will make no mention of the eutectic formations in its final report into the WTC collapses, released in late 2005, following its three-year investigation. [National Institute of Standards and Technology, 9/2005, pp. 13]

Entity Tags: National Institute of Standards and Technology, World Trade Center, Federal Emergency Management Agency

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation

The New York Times reports that “some of the nation’s leading structural engineers and fire-safety experts” believe the investigation into the collapse of the WTC is “inadequate” and “are calling for a new, independent and better-financed inquiry that could produce the kinds of conclusions vital for skyscrapers and future buildings nationwide.” Experts critical of the investigation include “some of those people who are actually conducting it.” They point out that the current team of 20 or so investigators has no subpoena power, inadequate financial support, and little staff support. Additionally, it has been prevented from interviewing witnesses and frequently prevented from examining the disaster site, and has even been unable to obtain basic information like detailed blueprints of the buildings that collapsed. The decision to recycle the steel columns, beams, and trusses from the WTC rapidly in the days immediately after 9/11 means definitive answers may never be known. [New York Times, 12/25/2001] Incredibly, some of the steel is reforged into commemorative medallions selling for $30 apiece. [Associated Press, 1/30/2002]

Entity Tags: World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

A firefighter trade magazine with ties to the New York Fire Department calls the investigation into the collapse of the WTC a “half-baked farce.” The article points out that the probe has not looked at all aspects of the disaster and has had limited access to documents and other evidence. “The destruction and removal of evidence must stop immediately.” The writer, Bill Manning, states, “I have combed through our national standard for fire investigation, NFPA 921, but nowhere in it does one find an exemption allowing the destruction of evidence for buildings over 10 stories tall.” He concludes that a growing number of fire protection engineers have theorized that “the structural damage from the planes and the explosive ignition of jet fuel in themselves were not enough to bring down the towers.” Yet, “[a]s things now stand and if they continue in such fashion, the investigation into the World Trade Center fire and collapse will amount to paper- and computer-generated hypotheticals.” [Fire Engineering, 1/2002; New York Daily News, 1/4/2002]

Entity Tags: New York City Fire Department, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

World Trade Center Building 7, which collapsed late in the afternoon of 9/11, had contained two independently supplied and operated fuel systems for emergency power. The fuel had been in several storage tanks low down in the building. In March and April, two 11,700-gallon tanks that had been located under the building’s first floor loading dock and operated by Silverstein Properties are removed from the collapse site. They show no evidence of fuel leakage. FEMA says that approximately 20,000 gallons of fuel are subsequently recovered from them, which is about 85 percent of their total capacity. In early May, two 6,000-gallon tanks that had been owned by Salomon Smith Barney and were also located below the loading dock are recovered. These were always kept full for emergencies and would have been full on 9/11. Yet now they are damaged and appear to be empty. According to the National Institute of Standards and Technology (NIST), “Some fuel contamination was found in the gravel below the tanks and sand below the slab on which the tanks were mounted, but no contamination was found in the organic marine silt/clay layer underneath.” Shyam Sunder, lead investigator of NIST’s WTC investigation, will state that this “suggests that this fuel… could have been consumed in the building.” This finding “allows for the possibility, though not conclusively, that the fuel may have contributed to a fire on Floor 5” of WTC 7. [Federal Emergency Management Agency, 5/1/2002, pp. 5-15; Associated Press, 6/6/2002; Newsday, 6/6/2002; National Institute of Standards and Technology, 4/5/2005 pdf file; New York City Council, 9/8/2006 pdf file] Some people have speculated that the diesel fuel stored in WTC 7 may have played a role in its collapse (see March 2, 2002). However, FEMA says, “Although the total diesel fuel on the premises contained massive potential energy, the best hypothesis has only a low probability of occurrence.” WTC 7 housed another 6,000-gallon tank between its second and third floors, which was meant to fuel generators that would supply backup power to the mayor’s 23rd-floor emergency command center (see June 8, 1999). Currently, no data are available on the condition of this tank. [Federal Emergency Management Agency, 5/1/2002, pp. 5-16 and 5-31]

Entity Tags: World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation

A New York Times article theorizes that diesel fuel tanks were responsible for the collapse of Building 7 of the WTC. It collapsed at 5:20 p.m. on 9/11, even though it was farther away from the Twin Towers than many other buildings that remained standing (see (5:20 p.m.) September 11, 2001). It was the first time a steel-reinforced high-rise in the US had ever collapsed in a fire. One of the fuel tanks had been installed in 1999 (see June 8, 1999) as part of a new “Command Center” for Mayor Rudolph Giuliani. [New York Times, 3/2/2002; Dow Jones Business News, 9/10/2002] However, in interviews, several Fire Department officers who were on the scene say they were not aware of any combustible liquid pool fires in WTC 7. [Fire Engineering, 9/2002] And, according to the National Institute of Standards and Technology (NIST), between 11:30 a.m. and 2:30 p.m. on 9/11, “No diesel smells [were] reported from the exterior, stairwells, or lobby areas” of WTC 7. [National Institute of Standards and Technology, 6/2004, pp. L-22 pdf file] Curiously, given all the Wall Street scandals later in the year, Building 7 housed the SEC files related to numerous Wall Street investigations, as well as other federal investigative files. All the files for approximately 3,000 to 4,000 SEC cases were destroyed. Some were backed up in other places, but many were not, especially those classified as confidential. [New York Law Journal, 9/17/2001] Lost files include documents that could show the relationship between Citigroup and the WorldCom bankruptcy. [Street, 8/9/2002] The Equal Employment Opportunity Commission estimates over 10,000 cases will be affected. [New York Law Journal, 9/14/2001] The Secret Service had its largest field office, with more than 200 employees, in WTC 7 and also lost investigative files. Says one agent: “All the evidence that we stored at 7 World Trade, in all our cases, went down with the building.” [Tech TV, 7/23/2002] The IRS and Department of Defense were also tenants, along with the CIA, which, it has been revealed, had a secret office in Building 7. [CNN, 11/4/2001; New York Times, 11/4/2001; Federal Emergency Management Agency, 5/1/2002, pp. 5-2; New York Magazine, 3/20/2006] A few days later, the head of the WTC collapse investigation says he “would possibly consider examining” the collapse of Building 7, but by this time all the rubble has already been removed and destroyed. [US Congress, 3/6/2002]

Entity Tags: Larry Silverstein, Citibank, Internal Revenue Service, US Securities and Exchange Commission, Central Intelligence Agency, US Secret Service, WorldCom, World Trade Center, US Department of Defense

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

The House Committee on Science holds a hearing on the investigation into the collapse of the World Trade Center on 9/11. Witnesses from industry, academia, and government testify on the collapses and the subsequent efforts to find out how and why they occurred. The hearings charter points out several problems that have severely hampered investigations. It says, “Early confusion over who was in charge of the [WTC collapse] site and the lack of authority of investigators to impound pieces of steel for examination before they were recycled led to the loss of important pieces of evidence that were destroyed early during the search and rescue effort.… Some of the critical pieces of steel—including the suspension trusses from the top of the towers and the internal support columns—were gone before the first BPAT [Building Performance Assessment Team] team member ever reached the site” (see September 12-October 2001). Furthermore, “The building owners, designers and insurers, prevented independent researchers from gaining access—and delayed the BPAT team in gaining access—to pertinent building documents largely because of liability concerns.” Regarding the decision to rapidly recycle the WTC steel, US Representative Joseph Crowley (D-NY) says, “I do believe that conspiracy theorists are going to have a field day with this,” and says this loss of important physical evidence “is not only unfortunate, it is borderline criminal.” In his statement before the committee, Glenn Corbett, a science professor at John Jay College, claims that the “lack of significant amounts of steel for examination will make it difficult, if not impossible, to make a definitive statement as to the cause and chronology of the collapse.” He also complains, “[W]e are staffing the BPAT with part-time engineers and scientists on a shoestring budget.” [US Congress, 3/6/2002; Associated Press, 3/7/2002]

Entity Tags: World Trade Center, Glenn Corbett, House Committee on Science, Joseph Crowley

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

A structural engineer who was a member of the team assembled by the American Society of Civil Engineers to investigate the World Trade Center site after 9/11 complains about the decision to rapidly destroy the remaining structural steel from the collapsed WTC buildings. Dr. Abolhassan Astaneh-Asl is a professor of civil and environmental engineering at the University of California at Berkeley, and specializes in studying structural damage done by earthquakes and terrorist bombings. [Chronicle of Higher Education, 12/7/2001; CBS News, 3/11/2002; Associated Press, 9/6/2002] He had come to New York a week after 9/11 to examine the collapsed towers, hoping to gain an understanding of how they had come down (see September 19-October 2001). [New York Times, 10/2/2001; US Congress. House. Committee on Science, 3/6/2002] However, New York City officials had decided early on to quickly transport the remaining structural steel to scrap yards, to be shipped abroad and melted down for reuse (see Shortly After September 11, 2001). As CBS News now reports, “As a result, Astaneh has almost certainly missed seeing crucial pieces before they were cut up and sent overseas.” Astaneh-Asl complains: “When there is a car accident and two people are killed, you keep the car until the trial is over. If a plane crashes, not only do you keep the plane, but you assemble all the pieces, take it to a hangar, and put it together. That’s only for 200, 300 people, when they die. In this case you had 3,000 people dead.” He says: “My wish was that we had spent whatever it takes, maybe $50 million, $100 million, and maybe two years, get all this steel, carry it to a lot. Instead of recycling it, put it horizontally, and assemble it. You have maybe 200 engineers, not just myself running around trying to figure out what’s going on. After all, this is a crime scene and you have to figure out exactly what happened for this crime, and learn from it.” However, he adds, “My wish is not what happens.” [CBS News, 3/12/2002] Astaneh-Asl previously told the New York Times that the scrap steel from the WTC was “worth only a few million dollars, a tiny fraction of the billions of dollars the cleanup will cost.” Yet the knowledge that could be gained from it “could save lives in a future disaster.” [New York Times, 10/2/2001]

Entity Tags: World Trade Center, Abolhassan Astaneh-Asl

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

FEMA’s World Trade Center Building Performance Study.FEMA’s World Trade Center Building Performance Study. [Source: FEMA]FEMA releases its report of the WTC collapses. It concludes, “[W]ith the information and time available, the sequence of events leading to the collapse of each tower could not be definitively determined.” On Building 7: “The specifics of the fires in WTC 7 and how they caused the building to collapse remain unknown at this time.” [Federal Emergency Management Agency, 5/1/2002]

Entity Tags: World Trade Center, Federal Emergency Management Agency

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

A brief ceremony marks the official ending of the cleanup and recovery effort at Ground Zero, eight months and 19 days after 9/11. As part of the ceremony, attended by thousands of people, a flatbed truck carries the last steel beam from the World Trade Center away from the site. The cleanup has been completed three months sooner than predicted and at a cost of $750 million. More than 108,000 truckloads of debris, comprising 1.8 million tons of steel and concrete, have been removed from the site. The debris was taken to the Fresh Kills landfill on Staten Island. Controversially, much of the steel was melted down or shipped out of the US for recycling (see September 12-October 2001). A small number of workers will remain at the site for a few more weeks, due to a delay by Deutsche Bank in letting firefighters search its high-rise at 130 Liberty Street. The final truckload of debris will be removed on June 24 and control of the site will be turned over to the New York Port Authority, which owns the land. Forensic investigators will continue sifting through debris at Fresh Kills, in the hope of finding and identifying more victims, until mid-July. [CBS News, 5/16/2002; CBS News, 5/30/2002; CNN, 5/30/2002; PBS, 5/30/2002; BBC, 7/15/2002; Glanz and Lipton, 2004, pp. 316-318; Stout, Vitchers, and Gray, 2006, pp. 219 and 226-227]

Entity Tags: World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

The New York City government decides that the audio and written records of the Fire Department’s actions on 9/11 should never be released to the general public. The New York Times has been trying to get copies of the materials, which include firsthand accounts given to Fire Department officials by scores of firefighters and chiefs. The city claims the firefighters were told their accounts would be kept confidential, but senior fire officials say they were never told that their remarks would be kept confidential. [New York Times, 7/23/2002] The records will be released in 2005 after a legal battle (see August 12, 2005).

Entity Tags: New York Times, New York City Fire Department, City of New York

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations


This picture of the hole created in the WTC by Flight 11 supports recordings indicating that fires weren’t burning out of control. In the close-up insert at the top left, note the person standing at the edge of the hole.
This picture of the hole created in the WTC by Flight 11 supports recordings indicating that fires weren’t burning out of control. In the close-up insert at the top left, note the person standing at the edge of the hole. [Source: unknown]A “lost tape” of radio messages from firefighters inside the WTC on 9/11 is made public. Supposedly, “city fire officials simply delayed listening” to this tape until after the official report on the fire department’s response to the attacks was published, and they still refuse to allow any officials to discuss the contents. The tape reveals that two firefighters were able to reach the crash site on the 78th floor of the South Tower. While there, “Chief Palmer could see only two pockets of fire, and called for a pair of engine companies to fight them.” [New York Times, 8/4/2002; Guardian, 8/5/2002]

Entity Tags: New York City Fire Department, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

The National Institute of Standards and Technology (NIST)—an agency of the US Commerce Department’s Technology Administration—announces details of its forthcoming investigation into the collapses of the World Trade Center Twin Towers and Building 7 on 9/11. The NIST investigation aims “to investigate the building construction, the materials used, and the technical conditions that contributed to the outcome of the World Trade Center (WTC) disaster.” It also aims to examine the activities of building occupants and emergency responders on 9/11, studying such issues as emergency communications within the WTC, the movement of people during the evacuations, and issues around persons with disabilities. Leading technical experts from industry, academia, and other laboratories, alongside NIST’s own expert staff, will participate in the investigation. Expert professionals from the private sector will also be involved. Glenn Corbett, a fire science professor at John Jay College, says, “This is going to be the most extensive building disaster investigation ever performed.” [Associated Press, 8/21/2002; National Institute of Standards and Technology, 8/21/2002; National Institute of Standards and Technology, 8/3/2005] The investigation is formally authorized in October 2002, when the National Construction Safety Team Act is signed into law. The act, which gives NIST authorization to investigate major building failures in the US, is written largely as a result of the World Trade Center collapses. [National Institute of Standards and Technology, 10/2/2002; New York Times, 5/8/2003] NIST’s investigation is originally proposed to last two years, with a budget of $16 million. [National Institute of Standards and Technology, 8/21/2002] However, it eventually will last three years, with its final report into the collapses of the Twin Towers being released in October 2005 (see October 26, 2005). A previous analysis of the WTC collapses conducted by FEMA and the American Society of Civil Engineers (ASCE) was completed earlier in 2002 (see May 1, 2002), but this had a budget of just $1.1 million. By the time NIST starts its investigation, much of the crucial steel debris from the WTC collapses has already been destroyed (see September 12-October 2001). They later refer to there being a “scarcity of physical evidence that is typically available in place for reconstruction of a disaster.” [National Institute of Standards and Technology, 9/2005, pp. xxxvi]

Entity Tags: World Trade Center, National Institute of Standards and Technology, Glenn Corbett

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

One of the key variables in the computer simulations used by the National Institute of Standards and Technology (NIST) (see (October 2002-October 2005)) to explain the WTC collapses is the speed of the aircraft that hit the towers. However, there is no consensus on how fast the planes were traveling. The first estimate was contained in an initial research paper by engineers Zdenek Bazant and Yong Zhou, who stated that the planes were traveling at 342 miles per hour. [Bazant and Zhou, 1/2002 pdf file] However, the Federal Emergency Management Agency (FEMA) and American Society of Civil Engineers (ASCE) report said that the plane that hit the North Tower was traveling at 470 miles per hour, whereas the plane that hit the South Tower was traveling at 590 miles per hour (see May 1, 2002). [Federal Emergency Management Agency, 5/1/2002, pp. 31] NIST initially estimates speeds of 435 miles per hour for the plane that hit the North Tower and 497 miles per hour for the plane that hit the South Tower. These estimates closely match figures produced by the Massachusetts Institute of Technology, which finds speeds of 429 miles per hour and 503 miles per hour for the two planes. However, NIST is dissatisfied with these results and does a second study, which finds speeds of 466 and 545 miles per hour. It then uses speeds of 472 and 570 miles per hour in its severe case model, on which its final report is based. In this model, the simulation of the planes traveling faster means greater damage to the towers’ structure, making them more unstable. [Kausel, 5/2002 pdf file; National Institute of Standards & Technology, 9/2005, pp. 152-165 pdf file; National Institute of Standards and Technology, 9/2005, pp. 109]

Entity Tags: Zdenek Bazant, National Institute of Standards and Technology, World Trade Center, Yong Zhou, Massachusetts Institute of Technology, American Society of Civil Engineers, Federal Emergency Management Agency

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

During the course of its three-year investigation of the World Trade Center collapses, the National Institute of Standards and Technology (NIST) performs computer simulations of the behavior of each WTC tower on 9/11. In its final report, released in October 2005 (see October 26, 2005), it will describe having determined which variables most affected the outcome of its various simulations. Then, “[f]or each of the most influential variables, a central or middle value and reasonable high and low values were identified.” However, “[u]pon a preliminary examination of the middle cases, it became clear that the towers would likely remain standing. The less severe cases were discarded after the aircraft impact results were compared to observed events. The middle cases… were discarded after the structural response analysis of major subsystems were compared to observed events.” Therefore, the “more severe case… was used for the global analysis of each tower.” But, to “the extent that the simulations deviated from the photographic evidence or eyewitness reports, the investigators adjusted the input, but only within the range of physical reality.” [National Institute of Standards and Technology, 9/2005, pp. 143-144]

Entity Tags: National Institute of Standards and Technology, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Matthys Levy.Matthys Levy. [Source: PBS]A report is made publicly available, which the Engineering News-Record calls the “most comprehensive study yet on the destruction of the World Trade Center.” The study was commissioned by WTC leaseholder Silverstein Properties Inc. to support a $7 billion insurance claim, and conducted by a team of engineers from several leading firms, including Weidlinger Associates, LZA Technology/Thornton-Tomasetti, and ARUPFire. It is intended to build on a previous study sponsored by FEMA (see May 1, 2002). The report’s findings are based on an analysis of original structural drawings, thousands of photos, and dozens of videos. Investigators used fire evaluation techniques and powerful computer software to simulate the condition of each tower at critical times between the planes’ impacts and the towers’ collapses. The earlier FEMA investigators had no access to such computer modeling. Matthys Levy, the chairman of Weidlinger Associates and one of the engineers on the study team, says, “The buildings had tremendous reserve capacity and that was reflected in all of the elements we analyzed. In fact, because there were so much excess capacity, the columns even in the impact floors did not buckle immediately, but failed as the result of the fire.” The report states that failure of the WTC’s steel floor supports (“trusses”) did not contribute to the collapses. Instead, the collapses were caused by the failure of steel structural columns that were either destroyed when the planes hit or lost fireproofing, leaving them vulnerable to the weakening effects of the ensuing fires. It says that debris and dust distributed by the plane crashes inhibited the fires, such that the average air temperatures on the impact floors were between 400 and 700°C (750-1,300°F): significantly lower than those associated with typical “fully developed” office fires. However, says Matthys Levy, “By the time the temperature inside the buildings reached 400 degrees, the steel would have lost approximately 50% of its strength. Eventually, gravity took over and the towers began to fall.” Then, according to the analysis led by researchers from LZA Technology/Thornton-Tomasetti, “Once collapse initiated in each tower, essentially all of the interior structure of the tower fell straight down with floors pancaking on top of one another. The network of perimeter steel columns and spandrels acted like a chute to funnel the interior contents into the tower footprint.” According to the computer simulations, the damage to the South Tower’s steel core columns was so severe that the tower should have collapsed immediately after the plane hit. Civil engineer John Osteraas says this incorrect result casts doubt upon some of the study’s predictions. The report concludes that the collapse of the South Tower did not cause or contribute to the subsequent collapse of the North Tower, thus supporting Silverstein Properties’ claim that the terrorist attack represented two occurrences, entitling it to two $3.5 billion insurance policy limits. A separate study commissioned by the insurers contradicts this (see October 23, 2002). The Silverstein report apparently does not examine the collapse of WTC Building 7, a 47-story skyscraper that also collapsed on 9/11 (see (5:20 p.m.) September 11, 2001). It has been passed on to the National Institute of Standards and Technology (NIST), which is undertaking its own investigation of the WTC collapses (see August 21, 2002). [New York Times, 9/30/2002; Business Insurance, 10/23/2002; Silverstein Properties, Inc., 10/23/2002 pdf file; Engineering News-Record, 10/25/2002; New York Times, 10/29/2002; Engineering News-Record, 11/4/2002; Real Estate Weekly, 4/30/2003]

Entity Tags: World Trade Center, Silverstein Properties, Thornton-Tomasetti Engineers, Weidlinger Associates, Matthys Levy

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

An engineering report is released concluding that the destruction of one of the World Trade Center’s Twin Towers would have rendered the other unusable. Swiss Re and other insurance companies involved in the WTC coverage commissioned the study, which was written by California-based Exponent Failure Analysis Associates. It is released the same day as a report on the collapses by WTC leaseholder Silverstein Properties Inc. (see October 23, 2002). Contradicting the Silverstein report, it concludes: “[T]he collapse of one tower in the World Trade Center complex would have severely compromised the future viability of the entire complex.” This supports the insurance companies’ contention that the WTC attacks constituted one loss event, not two, as claimed by Silverstein Properties, thereby entitling Silverstein to a policy limit of $3.5 billion instead of $7 billion. The report, along with the underlying data, computer models, and engineering analyses, have been passed on to the National Institute of Standards and Technology (NIST), which is conducting an investigation into the collapses (see August 21, 2002). [Business Insurance, 10/23/2002; Insurance Journal, 10/23/2002; Engineering News-Record, 11/4/2002] In late 2004, a jury will rule that the WTC attacks were two events, and Silverstein Properties will be tentatively awarded $2.2 billion in insurance for the destruction of the Twin Towers. [BBC, 12/7/2004; Insurance Journal, 12/7/2004]

Entity Tags: Silverstein Properties, Exponent Failure Analysis Associates, Swiss Reinsurance, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Related Lawsuits, 9/11 Investigations

Insulated trusses in the World Trade Center.
Insulated trusses in the World Trade Center. [Source: Gilsanz Murray Steficek]At a press briefing in New York City, the National Institute of Standards and Technology (NIST) releases a 122-page progress report on its investigation into the WTC collapses. NIST began its study in August 2002 (see August 21, 2002). Investigators say they believe that the Port Authority of New York and New Jersey, who built the Twin Towers, failed to carry out vital tests to establish how the buildings would cope with a major fire. They have been unable to find evidence that tests were conducted on the fireproofing material used in the buildings. Their report also states that in 1969, builders directed contractors to coat the WTC floor supports with half an inch of spray-on fireproofing. In 1999, the Port Authority issued guidelines to triple the thickness of the fireproofing, and by 9/11, about 30 floors in the upper areas of the two towers had been upgraded. Almost all the floors in the impact zone of the North Tower had their fireproofing upgraded, while in the South Tower just the 78th floor—the lowest in its impact zone—had been upgraded. As the New York Times states, though, “investigators took great care… to say they were nowhere close to definitively determining how and why the towers collapsed after they were struck by hijacked airliners.” [National Institute of Standards and Technology, 5/2003, pp. 81 pdf file; National Institute of Standards and Technology, 5/7/2003; Guardian, 5/8/2003; New York Times, 5/8/2003]

Entity Tags: National Institute of Standards and Technology, Port Authority of New York and New Jersey, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

At the end of a two-day meeting to discuss the progress of their investigation of the WTC collapses on 9/11, National Institute of Standards and Technology (NIST) investigators say that early tests on steel beams recovered from the World Trade Center showed they met or were stronger than design requirements. NIST has collected 236 pieces of steel from the wreckage of the towers. Tests have found that the steel beams exceeded requirements to bear 36,000 pounds per square inch, and were often capable of bearing around 42,000 pounds per square inch. Lead investigator Shyam Sunder says that if further testing corroborates these findings, this will rule out weak steel as a factor in the collapses. [National Institute of Standards and Technology, 8/26/2003; Associated Press, 8/28/2003] The final report of the NIST investigation, released in 2005, will corroborate this finding: “Overall, approximately 87 percent of all perimeter and core column steel tested exceeded the required minimum yield strengths specified in design documents. Test data for the remaining samples were below specifications, but were within the expected variability and did not affect the safety of the towers on September 11, 2001.” It also will point out: “Of the more than 170 areas examined on 16 perimeter column panels, only three columns had evidence that the steel reached temperatures above 250°C.… Only two core column specimens had sufficient paint remaining to make such an analysis, and their temperatures did not reach 250°C.… Using metallographic analysis, NIST determined that there was no evidence that any of the samples had reached temperatures above 600 °C.” [National Institute of Standards and Technology, 9/2005, pp. 89-90]

Entity Tags: World Trade Center, National Institute of Standards and Technology

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

An optical microscopy image of a particle in the WTC dust formed by high temperature.An optical microscopy image of a particle in the WTC dust formed by high temperature. [Source: RJ Lee Group]A laboratory releases two reports focusing on the unique properties of the dust from the World Trade Center collapses, and finds evidence of extremely high temperatures involved in these collapses. The laboratory, RJ Lee Group of Pennsylvania, is the largest commercial electron microscope laboratory in the world. [RJ LeeGroup, Inc., 5/2004, pp. 1 pdf file] In April 2002, it was retained on behalf of Deutsche Bank Trust Company Americas to investigate environmental contaminants in this company’s building at 130 Liberty Street, New York. [RJ LeeGroup, Inc., 12/2003, pp. 1 pdf file] The building, located next to the World Trade Center, was heavily damaged on September 11, suffering a 24-story gash when the South Tower collapsed. [New York Times, 6/20/2003; Real Estate Weekly, 9/14/2005] RJ Lee collected samples from it, which it then analyzed “using industry standard analytical laboratory methods.” [RJ LeeGroup, Inc., 12/2003, pp. 3-4 pdf file] In December 2003 and May 2004, it releases two reports that evaluate the features of the dust from the WTC that was deposited in 130 Liberty Street. It calls this evaluation “the most extensive microscopic investigation related to WTC dust ever performed.” [RJ LeeGroup, Inc., 12/2003, pp. 1-2 pdf file; RJ LeeGroup, Inc., 5/2004, pp. 4 pdf file] The reports describe phenomena that indicate extremely high temperatures were involved in the WTC collapses:
bullet “Various metals (most notably iron and lead) were melted during the WTC event, producing spherical metallic particles. Exposure of phases to high heat results in the formation of spherical particles due to surface tension.” [RJ LeeGroup, Inc., 12/2003, pp. 17 pdf file]
bullet “The amount of energy introduced during the generation of the WTC dust and the ensuing conflagration caused various components to vaporize.… Many of the materials, such as lead, cadmium, mercury, and various organic compounds, vaporized and then condensed during the WTC event.” [RJ LeeGroup, Inc., 12/2003, pp. 21 pdf file]
bullet “An additional characteristic of WTC dust is the presence of coated particles and fibers.… The presence of lead oxide on the surface of mineral wool indicate the existence of extremely high temperatures during the collapse which caused metallic lead to volatilize, oxidize, and finally condense on the surface of the mineral wool.” [RJ LeeGroup, Inc., 5/2004, pp. 12 pdf file]
bullet “WTC dust markers exhibit characteristics of particles that have undergone high stress and high temperature. Asbestos in the WTC dust was reduced to thin bundles and fibrils as opposed to the complex particles found in a building having asbestos-containing surfacing materials. Gypsum in the WTC dust is finely pulverized to a degree not seen in other building debris. Mineral wool fibers have a short and fractured nature that can be attributed to the catastrophic collapse. Lead was present as ultra fine spherical particles. Some particles show evidence of being exposed to a conflagration such as spherical metals and silicates, and vesicular particles (round open porous structure having a Swiss cheese appearance as a result of boiling and evaporation).” [RJ LeeGroup, Inc., 5/2004, pp. 17-18 pdf file]
The reports offer no explanation for the origins of the extremely high temperatures that are indicated. But physics professor Steven E. Jones (see November 8, 2005) will later claim that molten metal found in the debris of the WTC is evidence that the towers were brought down deliberately and involving the use of an incendiary substance called thermite, which can melt steel. [Deseret Morning News, 11/10/2005; Deseret Morning News, 4/10/2006]

Entity Tags: World Trade Center, RJ Lee Group

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

The National Institute of Standards and Technology (NIST) issues a progress report on its investigation into the World Trade Center collapses. Since 2002, NIST has been investigating the collapses of the Twin Towers and WTC Building 7 (see August 21, 2002). The progress report includes its “working hypothesis” for the collapse of WTC 7. This was a 47-story building, located about 350 feet from the north side of WTC 1, which collapsed completely at around 5:20 in the afternoon of 9/11. The report claims that “fire appears to have played a key role” in the collapse, though it points out, “No fire was observed or reported in the afternoon on floors 1-5, 10, or above Floor 13.” It also says, “there may have been some physical damage on the south side of the building.” NIST summarizes its working hypothesis of the WTC 7 collapse as follows:
bullet “An initial local failure at the lower floors (below Floor 13) of the building due to fire and/or debris induced structural damage of a critical column (the initiating event), which supported a large span floor bay with an area of about 2,000 square feet.”
bullet “Vertical progression of the initial local failure up to the east penthouse, as large floor bays were unable to redistribute the loads, bringing down the interior structure below the east penthouse.”
bullet “Horizontal progression of the failure across the lower floors… triggered by damage due to the vertical failure, resulting in the disproportionate collapse of the entire structure.”
NIST claims this hypothesis “is consistent with all evidence currently held by NIST, including photographs and videos, eyewitness accounts and emergency communication records,” but says it “will be revised and updated as results of ongoing, more comprehensive analyses become available.” [National Institute of Standards and Technology, 6/2004, pp. L1, L3, L17, L34, L38, L51-L52 pdf file; National Institute of Standards and Technology, 6/18/2004] NIST will release its final reports on the collapses of the Twin Towers in October 2005 (see October 26, 2005). As of mid-2007, it has yet to release a final report on the collapse of WTC 7. In early 2006, Dr. S. Shyam Sunder, who is the lead investigator for NIST’s WTC investigation, will admit, “truthfully, I don’t really know” what caused WTC 7 to collapse. He will add, “We’ve had trouble getting a handle on building no. 7” (see March 20, 2006). [New York Magazine, 3/20/2006] An earlier report on the WTC collapses, released by the Federal Emergency Management Agency (FEMA) in May 2002, had been inconclusive on what caused WTC 7 to collapse, and stated that “Further research, investigation, and analyses” were necessary (see May 1, 2002). [Federal Emergency Management Agency, 5/1/2002, pp. 5-31]

Entity Tags: World Trade Center, National Institute of Standards and Technology

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Shyam Sunder.Shyam Sunder. [Source: NIST]The National Institute of Standards and Technology (NIST) releases nearly 500 pages of documents, detailing the latest findings of its investigation of the WTC collapses on 9/11. These include its hypotheses for the collapse sequences of each of the Twin Towers; details of their analysis of interviews with nearly 1,200 building occupants, emergency responders, and victims’ relatives; and information from their analysis of the emergency response and evacuation procedures. Their investigation into the collapses is based upon an analysis of thousands of photos and videos, examination of many of the elements used to construct the towers, and computer-enhanced modeling of the plane impacts and the spreading of the fires. Their hypothesis is that the towers collapsed ultimately due to the fires they suffered: As the fires burned, the buildings’ steel core columns buckled and shortened. This shifted more load to the buildings’ perimeter columns, which were already affected by the heat of the fires, and caused them to give way under the increased stress. Investigators have conducted a test with a reconstructed section of the WTC floor, and found that the original fireproofing was sufficient to meet the New York City building code. They say that had a typical office fire occurred in the towers, without the structural damage and the loss of some fireproofing caused by the plane impacts, it is likely the buildings would have remained standing. Lead investigator Dr. Shyam Sunder says, “The buildings performed as they should have in the airplane impact and extreme fires to which they were subjected. There is nothing there that stands out as abnormal.” NIST’s theories of why the WTC buildings collapsed conflict with an earlier investigation by FEMA, which claimed the collapse of the North Tower had begun in its core, rather than its perimeter columns (see May 1, 2002). [National Institute of Standards and Technology, 10/19/2004; New York Times, 10/20/2004]

Entity Tags: Shyam Sunder, National Institute of Standards and Technology, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations


Jimmy Walter.
Jimmy Walter. [Source: Publicity photo]Jimmy Walter, a millionaire from California, spends more than $5 million promoting the theory that there was a US government conspiracy behind the 9/11 attacks. Walter, the heir to an $11 million fortune, runs full-page adverts in the New York Times, the Wall Street Journal, the New Yorker, and Newsweek. He also runs television adverts: One of these questions why Building 7 of the World Trade Center collapsed on 9/11 despite not being hit by any plane, another suggests that Flight 77 never flew into the Pentagon. He offers a prize of $1 million to anyone who can prove that the WTC buildings collapsed in the way the US government says, without the use of explosives. Walter tells the New York Times, “It just isn’t possible that 19 screw-ups with box cutters pulled this whole thing off.” He also helped to pay for a Zogby poll, which found two-thirds of New Yorkers wanted the 9/11 investigation reopened (see August 30, 2004). [New York Times, 11/8/2004; CNN, 11/10/2004; CNN, 11/11/2004; Reuters, 12/16/2004; Sydney Morning Herald, 11/21/2005]

Entity Tags: Jimmy Walter

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, US Government and 9/11 Criticism

Kevin Ryan.Kevin Ryan. [Source: Public domain]Kevin Ryan, the laboratory director at Environmental Health Laboratories Inc., which is a subsidiary of Underwriters Laboratories Inc., writes an e-mail to the National Institute of Standards and Technology (NIST)—the agency currently investigating the WTC collapses—in which he challenges the official theory regarding the WTC collapses. According to Ryan, Underwriters Laboratories Inc. was the company that certified the steel components used in the construction of the World Trade Center, and it had been agreed that the samples it certified met all requirements. His e-mail states, “This story just does not add up. If steel from [the Twin Towers] did soften or melt, I’m sure we can all agree that this was certainly not due to jet fuel fires of any kind, let alone the briefly burning fires in those towers.” His e-mail is published on the Internet, and generates interest on many websites. Days later, Kevin Ryan is fired because, according to a company spokesman, he “expressed his own opinions as though they were institutional opinions and beliefs” of Underwriters Laboratories. According to Underwriters Laboratories, “there is no evidence” that any firm tested the materials used to build the towers. They also say that Ryan was not involved in any way with their fire protection division, which had conducted testing at NIST’s request. [South Bend Tribune, 11/22/2004]

Entity Tags: National Institute of Standards and Technology, Underwriters Laboratories Inc., Kevin Ryan, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

The National Institute of Standards and Technology (NIST), which is conducting an investigation into the WTC collapses on 9/11, releases three new reports. Investigators say that the Twin Towers would probably have remained standing if the fireproofing material that surrounded the buildings’ structural steel had not been stripped away when the planes hit. Their report states that “[t]he jet fuel, which ignited the fires, was mostly consumed within the first few minutes after impact. The fires that burned for almost the entire time that the buildings remained standing were due mainly to burning building contents and, to a lesser extent, aircraft contents, not jet fuel.” However, they claim, without the loss of fireproofing during the planes’ impacts, the heat from the fires would have been insufficient to cause the buildings to collapse. They say that although the architects had in 1964 tested the impact of a Boeing 707 airplane crashing into the 80th floor of one of the towers, they never envisioned the intense fires that ensued. NIST also reports that the time taken by survivors from the North Tower to descend a flight of stairs was about double the slowest evacuation speed estimated in a standard fire engineering text. They state: “approximately 87 percent of the WTC tower occupants, including more than 99 percent below the floors of impact, were able to evacuate successfully.” However, they say, if each tower had been full when they were hit, as many as 14,000 people could have died. [National Institute of Standards and Technology, 4/5/2005; Associated Press, 4/5/2005; New York Times, 4/5/2005; Associated Press, 4/6/2005]

Entity Tags: World Trade Center, National Institute of Standards and Technology

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Morgan Reynolds.Morgan Reynolds. [Source: Public Domain]Morgan Reynolds, chief economist for the Department of Labor during President George W. Bush’s first term, comments that the official story about the collapse of the World Trade Center is “bogus” and that it is more likely that a controlled demolition destroyed the Twin Towers and adjacent Building 7. Reynolds, who also served as director of the Criminal Justice Center at the National Center for Policy Analysis in Dallas and is now professor emeritus at Texas A&M University, says, “If demolition destroyed three steel skyscrapers at the World Trade Center on 9/11, then the case for an ‘inside job’ and a government attack on America would be compelling.” Reynolds comments: “It is hard to exaggerate the importance of a scientific debate over the cause of the collapse of the Twin Towers and Building 7. If the official wisdom on the collapses is wrong, as I believe it is, then policy based on such erroneous engineering analysis is not likely to be correct either. The government’s collapse theory is highly vulnerable on its own terms. Only professional demolition appears to account for the full range of facts associated with the collapse of the three buildings.” [Washington Times, 6/14/2005]

Entity Tags: Morgan Reynolds

Category Tags: US Government and 9/11 Criticism, WTC Investigation

Based upon its three-year investigation of the WTC collapses, the National Institute of Standards and Technology (NIST) calls for changes in the planning, construction, and operation of skyscrapers. NIST releases 43 draft reports, totaling about 10,000 pages, for public comments. These include 25 pages of recommendations, intended to learn from 9/11 and make building occupants and emergency responders safer in any future disasters. NIST’s inquiry has been conducted by more than 200 technical experts and contractors, and had two main parts: to look at the causes of the collapses and to identify weaknesses in building codes. Their recommendations include specific improvements to building standards, codes and practices; changes to evacuation and emergency response procedures; and research to help prevent future building failures. NIST does not have the authority to change building codes, but hopes to influence the policies of local authorities. The cost of implementing their recommended changes would add an estimated extra 2 to 5 percent to the development costs of buildings. Some are critical of their recommendations. Structural engineer Jon Magnusson, whose firm is the descendant of the company that designed the Twin Towers, says, “They are leading the public down the wrong path. They are saying we are going to fix the codes in order to deal with Sept. 11th. The physics say that you can’t do that.” [New York Times, 6/22/2005; National Institute of Standards and Technology, 6/23/2005; Associated Press, 6/24/2005] The New York Times points out that between 1989 and 1999, only five civilians had been killed in some 6,900 reported high-rise office building fires within the US. [New York Times, 6/24/2005] NIST will release its final report on the Twin Towers collapses four months later (see October 26, 2005).

Entity Tags: National Institute of Standards and Technology, World Trade Center, Jon Magnusson

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

The City of New York releases a large volume of records from 9/11. These include over 12,000 pages of oral histories—testimonies from 503 firefighters, paramedics, and emergency medical technicians involved in the 9/11 emergency response—and about 15 hours of radio communications between dispatchers and firefighters. The oral histories were gathered in informal interviews by the New York City Fire Department, beginning in October 2001. This was on the order of then Fire Commissioner Thomas Von Essen, who said he wanted to preserve the accounts before individual memories faded. However, these histories were never subsequently used for any official purpose. [New York Times, 8/12/2005; BBC, 8/13/2005; Guardian, 8/13/2005; Newsday, 8/13/2005] The New York Times, under the freedom of information law, originally sought the records in February 2002. Mayor Michael Bloomberg’s administration refused the request, claiming their release would jeopardize the prosecution of Zacarias Moussaoui, and violate firefighters’ privacy (see July 23, 2002). The newspaper, joined by some 9/11 victims’ relatives, consequently sued the city, and in March 2005 the state’s highest court ruled that the city had to release the oral histories and recordings, but could edit out potentially painful and embarrassing portions. The city had also initially refused investigators from the 9/11 Commission and the National Institute of Standards and Technology (NIST) access to the records, but relented following threats of legal action. [Associated Press, 8/12/2005; New York Times, 8/12/2005; Guardian, 8/13/2005] Analyzing the oral histories, the New York Times strongly criticizes the lack of information that firefighters received on 9/11: “[F]irefighters in the [north WTC tower] said they were ‘clueless’ and knew ‘absolutely nothing’ about the reality of the gathering crisis.” It continues: “Of 58 firefighters who escaped the [North Tower] and gave oral histories, only four said they knew the South Tower had already fallen. Just three said they had heard radio warnings that the North Tower was also in danger of collapse. And some who had heard orders to evacuate debated whether they were meant for civilians or firefighters.” [New York Times, 9/9/2005]

Entity Tags: City of New York, New York City Fire Department, Thomas Von Essen

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Both towers of the World Trade Center tilted to one side before beginning to fall on 9/11 (see 9:59 a.m. September 11, 2001 and 10:28 a.m. September 11, 2001). The National Institute of Standards and Technology, which investigated the collapses (see August 21, 2002), states that the South Tower, which was hit on its south side, tilted about 7-8 degrees to the east and 3-4 degrees to the south, and the North Tower, which was hit on its north side, tilted about 8 degrees to the south, before starting to fall. [National Institute of Standards and Technology, 9/2005, pp. 300, 308 pdf file] However, these findings are criticized by Canadian scientist Frank Greening. After examining photo and video evidence, Greening says that the South Tower tilted by no more than two degrees and the North Tower by no more than three degrees before collapse initiation. Greening also says that the tilt angles NIST gives cannot correspond to the downward movement of the towers’ walls NIST claims before they started to fall, and points out that the tilt angles NIST uses are inconsistent throughout its reports. Though Greening agrees with NIST that the towers were destroyed by the plane impacts and fire damage, he concludes that its computer model is “highly inaccurate and therefore of no value in explaining the demise of the Twin Towers.” [Greening, 11/2005 pdf file] Greening is a leading figure in the post-9/11 dispute over why the WTC collapsed and publishes a series of papers dealing with various aspects of the Twin Towers’ collapse. For example, a CBC documentary uses Greening for analysis of the WTC’s fall. [Canadian Broadcasting Corporation, 8/25/2005]

Entity Tags: World Trade Center, Frank Greening, National Institute of Standards and Technology

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

The British publication New Civil Engineer reports that, despite calls from leading structural and fire engineers, WTC collapse investigators with the National Institute of Standards and Technology (NIST) are refusing to show computer visualizations of the Twin Towers’ collapses. Despite having shown detailed computer generated visualizations of the plane impacts and the development of fires in the WTC at a recent conference, it showed no visualizations of the actual collapse mechanisms of the towers. Colin Bailey, a professor of structural engineering at the University of Manchester, complains, “NIST should really show the visualisations; otherwise the opportunity to correlate them back to the video evidence and identify any errors in the modelling will be lost.” A leading US structural engineer says that NIST’s “global structural model” is less sophisticated than its plane impact and fire models: “The software used has been pushed to new limits, and there have been a lot of simplifications, extrapolations and judgement calls.” [New Civil Engineer, 10/6/2005]

Entity Tags: World Trade Center, National Institute of Standards and Technology, Colin Bailey

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

James Quintiere.James Quintiere. [Source: University of Maryland]During a House Science Committee hearing on the key findings and recommendations of the National Institute of Standard and Technology (NIST) investigation into World Trade Center collapse, a fire expert raises several concerns. James Quintiere is a professor of fire protection engineering at the University of Maryland, with over 35 years of experience in fire research. He’d worked in the fire program at NIST for 19 years, and is a former chair of the International Association for Fire Safety Science, which is the principal world forum for fire research. In his statement presented at the hearing, Quintiere lists several specific concerns that he’d submitted to NIST, but which were never acknowledged or answered. These include:
bullet “Why were not alternative collapse hypotheses investigated and discussed as NIST had stated repeatedly that they would do?”
bullet “Spoliation of a fire scene is a basis for destroying a legal case in an investigation. Most of the steel [from the WTC] was discarded.… A careful reading of the NIST report shows that they have no evidence that the temperatures they predict as necessary for failure are corroborated by findings of the little steel debris they have.”
bullet “NIST used computer models that they said have never been used in such an application before and are the state of the art.… But the validation of these modeling results is in question.”
bullet “The critical collapse of WTC 7 is relegated to a secondary role.… Why has NIST dragged on this important investigation?”
Quintiere also complains, “In my opinion, the WTC investigation by NIST falls short of expectations by not definitively finding cause, by not sufficiently linking recommendations of specificity to cause, by not fully invoking all of their authority to seek facts in the investigation, and by the guidance of government lawyers to deter rather than develop fact finding.” [US Congress. House. Committee on Science, 10/26/2005]

Entity Tags: World Trade Center, James Quintiere, National Institute of Standards and Technology

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

The 43 NIST reports ran to over 10,000 pages.The 43 NIST reports ran to over 10,000 pages. [Source: NIST]The National Institute of Standards and Technology (NIST) issues the final report of its three-year, $16 million study into the WTC collapses on 9/11. NIST has produced over 10,000 pages of findings, and its report includes 30 recommendations for improving building safety, such as having wider stairwells and structurally hardened elevators for use in emergencies. The recommendations are mostly the same as those outlined in an earlier draft of the report (see June 23, 2005). [Engineering News-Record, 10/27/2005; New York Times, 10/27/2005] NIST has made some amendments and clarifications, though, based upon nearly 500 comments received during a six-week public review period. [National Institute of Standards and Technology, 10/26/2005] NIST’s theory about what caused the Twin Towers to collapse remains the same as that described in its previously released findings (see October 19, 2004). However, the NIST’s account only examines events up to the initiation of each collapse; the investigation “does not actually include the structural behavior of the tower after the conditions for collapse initiation were reached and collapse became inevitable.” [National Institute of Standards and Technology, 9/2005, pp. 82] NIST makes no mention of molten metal found at the collapse site in the weeks and months after 9/11, which has been described in numerous reports (see September 12, 2001-February 2002). The “NIST found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001.” [National Institute of Standards and Technology, 9/2005, pp. 146] Members of Congress are critical of NIST’s recommendations, saying they are not detailed enough, or adequately documented, to be rapidly incorporated into standard building code publications. [New York Times, 10/27/2005] According to Glenn Corbett, a technical adviser to NIST and fire science professor at John Jay College, NIST is not aggressive enough to carry out major forensic investigations. He says, “Instead of a gumshoe inquiry that left no stone unturned, I believe the investigations were treated more like research projects in which they waited for information to flow to them.” [Associated Press, 10/26/2005; US Congress, 10/26/2005 pdf file] NIST will release its final report on the collapse of Building 7 of the WTC separately, at a later date. [National Institute of Standards and Technology, 9/2005, pp. xiii]

Entity Tags: World Trade Center, Glenn Corbett, National Institute of Standards and Technology

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

National Institute of Standards and Technology (NIST) releases a 12-page appendix to its final reports on the WTC collapses (see October 26, 2005) detailing tests it conducted on samples of the type of fireproofing used in the WTC. An earlier NIST report had concluded that loss of fireproofing was a major factor in the collapses (see April 5, 2005). The appendix was not included in earlier drafts of the report (see June 23, 2005) [National Institute of Standards and Technology, 6/23/2005 pdf file; National Institute of Standards & Technology, 9/2005, pp. 263-274 pdf file; National Institute of Standards and Technology, 9/2005, pp. 149] NIST conducted a series of fifteen tests. In the tests projectiles were fired at fireproofing mounted on 12 inch x 12 inch plates, and steel bars with a one inch diameter. The fireproofing used in the tests was Blazeshield DC/F, one of the two grades of fireproofing used on the impact floors. In thirteen of the tests the projectiles were buckshot, which was fired at the steel samples from a modified shotgun at a distance of 29.5 ft. The other two tests used steel bolts and hexagon nuts, fired with less velocity and at closer range. According to NIST, “The test results support the assumption that, within the debris field created by the aircraft impact into WTC 1 and WTC 2, the SFRM [i.e., fireproofing] used for thermal insulation of structural members was damaged and dislodged.” [National Institute of Standards & Technology, 9/2005, pp. 83, 263-274 pdf file]

Entity Tags: National Institute of Standards and Technology, World Trade Center

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Steven E. Jones.Steven E. Jones. [Source: Publicity photo]Steven E. Jones, a 20-year physics professor at Brigham Young University in Utah, posts a 9,000-word academic paper on the Internet, in which he says it is likely there were explosives in the three WTC towers that collapsed on 9/11. In his paper, which has been accepted for peer-reviewed publication in 2006, he states, “It is quite plausible that explosives were pre-planted in all three buildings and set off after the two plane crashes—which were actually a diversion tactic.… Muslims are (probably) not to blame for bringing down the WTC buildings after all.” He says the official explanation for the collapses—that fires and structural damage caused them—cannot be backed up by either testing or history. The Pittsburgh Tribune-Review will comment, “Jones isn’t the first to make this shocking/unbelievable claim… But it’s hard to imagine anyone making it clearer.” Jones, who conducts research in fusion and solar energy, wants a new, independent investigation into what caused the collapses. [Deseret Morning News, 11/10/2005; KUTV 2 (Salt Lake City), 11/10/2005; MSNBC, 11/16/2005; Pittsburgh Tribune-Review, 11/20/2005]

Entity Tags: World Trade Center, Steven E. Jones

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, US Government and 9/11 Criticism, 9/11 Investigations

Dr. S. Shyam Sunder, head of the National Institute of Standards and Technology government investigation into the collapse of the World Trade Center building, is asked about the collapse of WTC Building 7. Sunder says that he hopes to release something about that by the end of 2006. He adds, NIST did have some “preliminary hypotheses… We are studying the horizontal movement east to west, internal to the structure, on the fifth to seventh floors.… But truthfully, I don’t really know. We’ve had trouble getting a handle on building No. 7.” [New York Magazine, 3/20/2006]

Entity Tags: Shyam Sunder, National Institute of Standards and Technology

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

Brent Blanchard, a leading professional and writer in the controlled demolition industry, publishes a 12-page report that says it refutes claims that the World Trade Center was destroyed with explosives. The report is published on ImplosionWorld.com, a demolition industry website edited by Blanchard. Blanchard is also director of field operations for Protec Documentation Services, Inc., a company specializing in monitoring construction-related demolitions. In his report, Blanchard says that Protec had portable field seismographs in “several sites in Manhattan and Brooklyn” on 9/11. He says they did not show the “spikes” that would have been caused by explosions in the towers. Blanchard also takes aim at the claim that Building 7 of the WTC was demolished, writing: “Several demolition teams had reached Ground Zero by 3:00 pm on 9/11, and these individuals witnessed the collapse of WTC 7 within a few hundred feet of the event. We have spoken with several who possess extensive experience in demolition, and all reported hearing or seeing nothing to indicate an explosive detonation precipitating the collapse.” However, Blanchard does not identify the demolition teams and the witnesses he spoke to. [ImplosionWorld.com, 8/8/2006 pdf file]
The report seems to receive official endorsement when it is later used as a source in a State Department debunking webpage entitled “The Top Ten September 11 Conspiracy Theories.” [International Herald Tribune, 9/2/2006; US State Department, 9/16/2006]

Entity Tags: US Department of State, Protec Documentation Services, Inc., Brent Blanchard, ImplosionWorld.com

Category Tags: WTC Investigation, 9/11 Investigations

One of the ‘puffs of smoke’ observed during the Twin Towers collapses.One of the ‘puffs of smoke’ observed during the Twin Towers collapses. [Source: Richard Lethin]The National Institute of Standards and Technology (NIST) issues a seven-page fact sheet to counter alternative theories about the WTC collapses. NIST conducted a three-year study of the collapses, and concluded they were caused by the damage when the planes hit combined with the effects of the ensuing fires. However, many people—what the New York Times calls an “angry minority”—believe there was US government complicity in 9/11, and a recent poll (see July 6-24, 2006) found 16 percent of Americans believe the WTC towers were brought down with explosives. [National Institute of Standards and Technology, 8/31/2006; New York Times, 9/2/2006; Reuters, 9/2/2006] The fact sheet responds to 14 “Frequently Asked Questions.” Some of its key points include the following:
bullet Regarding whether NIST considered a controlled demolition hypothesis: “NIST found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down… using explosives… Instead, photographs and videos from several angles clearly show that the collapse initiated at the fire and impact floors and that the collapse progressed from the initiating floors downward until the dust clouds obscured the view.” However, it admits, “NIST did not test for the residue” of explosives in the remaining steel from the towers.
bullet Its explanation for puffs of smoke seen coming from each tower as it collapsed: “[T]he falling mass of the building compressed the air ahead of it—much like the action of a piston—forcing smoke and debris out the windows as the stories below failed sequentially.”
bullet Its explanation for a stream of yellow molten metal that poured down the side of the South Tower shortly before it collapsed (see (9:50 a.m.) September 11, 2001). NIST previously claimed it was aluminum, but this should not have been yellow in color: “Pure liquid aluminum would be expected to appear silvery. However, the molten metal was very likely mixed with large amounts of hot, partially burned, solid organic materials (e.g., furniture, carpets, partitions and computers) which can display an orange glow.”
bullet Regarding reports of molten steel in the wreckage at Ground Zero (see September 12, 2001-February 2002): “Any molten steel in the wreckage was more likely due to the high temperature resulting from long exposure to combustion within the pile than to short exposure to fires or explosions while the buildings were standing.”
bullet Regarding the collapse of WTC 7 (see (5:20 p.m.) September 11, 2001): “While NIST has found no evidence of a blast or controlled demolition event, NIST would like to determine the magnitude of hypothetical blast scenarios that could have led to the structural failure of one or more critical elements.” [National Institute of Standards and Technology, 8/30/2006] In response to the fact sheet, Kevin Ryan, the coeditor of the online Journal of 9/11 Studies, says, “The list of answers NIST has provided is generating more questions, and more skepticism, than ever before.” He says, “NIST is a group of government scientists whose leaders are Bush appointees, and therefore their report is not likely to veer from the political story.” [New York Times, 9/2/2006; Reuters, 9/2/2006]

Entity Tags: National Institute of Standards and Technology, Kevin Ryan

Timeline Tags: 9/11 Timeline

Category Tags: WTC Investigation, 9/11 Investigations

A leading current affairs program on Dutch television says that 9/11 was a governmental conspiracy. The program is entitled “Zembla: Het complot van 11 september.” Zembla is a weekly investigative report shown on the public broadcasting network VARA. (A version of the program with English subtitles is available on Zembla’s website.) The program’s highlight is an interview with Danny Jowenko, a Dutch expert and industry professional in demolition. When shown a video of the collapse of Building 7 of the World Trade Center, he concludes that it is undoubtedly the work of a professional demolition team. [Vara, 9/10/2006]

Entity Tags: Danny Jowenko, Zembla

Category Tags: US Government and 9/11 Criticism, WTC Investigation

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Key Events

Key Day of 9/11 Events (101)Key Hijacker Events (145)Key Warnings (95)

Day of 9/11

All Day of 9/11 Events (1250)Dick Cheney (53)Donald Rumsfeld (33)Flight AA 11 (145)Flight AA 77 (145)Flight UA 175 (87)Flight UA 93 (241)George Bush (121)Passenger Phone Calls (67)Pentagon (117)Richard Clarke (31)Shanksville, Pennsylvania (23)Training Exercises (56)World Trade Center (87)

The Alleged 9/11 Hijackers

Alhazmi and Almihdhar (343)Marwan Alshehhi (134)Mohamed Atta (205)Hani Hanjour (72)Ziad Jarrah (74)Other 9/11 Hijackers (172)Possible Hijacker Associates in US (79)Alleged Hijackers' Flight Training (73)Hijacker Contact w Government in US (33)Possible 9/11 Hijacker Funding (42)Hijacker Visas and Immigration (135)

Alhazmi and Almihdhar: Specific Cases

Bayoumi and Basnan Saudi Connection (51)CIA Hiding Alhazmi & Almihdhar (120)Search for Alhazmi/ Almihdhar in US (39)

Projects and Programs

Al-Qaeda Malaysia Summit (172)Able Danger (60)Sibel Edmonds (61)Phoenix Memo (27)Randy Glass/ Diamondback (8)Robert Wright and Vulgar Betrayal (67)Remote Surveillance (241)Yemen Hub (75)

Before 9/11

Soviet-Afghan War (105)Warning Signs (432)Insider Trading/ Foreknowledge (53)US Air Security (71)Military Exercises (67)Pipeline Politics (67)Other Pre-9/11 Events (55)

Counterterrorism before 9/11

Hunt for Bin Laden (158)Counterterrorism Action Before 9/11 (223)Counterterrorism Policy/Politics (249)

Warning Signs: Specific Cases

Foreign Intelligence Warnings (35)Bush's Aug. 6, 2001 PDB (39)Presidential Level Warnings (31)

The Post-9/11 World

9/11 Investigations (651)9/11 Related Criminal Proceedings (22)9/11 Denials (29)US Government and 9/11 Criticism (67)9/11 Related Lawsuits (24)Media (47)Other Post-9/11 Events (76)

Investigations: Specific Cases

9/11 Commission (257)Role of Philip Zelikow (87)9/11 Congressional Inquiry (41)CIA OIG 9/11 Report (16)FBI 9/11 Investigation (144)WTC Investigation (112)Other 9/11 Investigations (128)

Possible Al-Qaeda-Linked Moles or Informants

Abu Hamza Al-Masri (102)Abu Qatada (36)Ali Mohamed (78)Haroon Rashid Aswat (17)Khalil Deek (20)Luai Sakra (12)Mamoun Darkazanli (36)Nabil Al-Marabh (41)Omar Bakri & Al-Muhajiroun (25)Reda Hassaine (23)Other Possible Moles or Informants (169)

Other Al-Qaeda-Linked Figures

Abu Zubaida (99)Anwar Al-Awlaki (17)Ayman Al-Zawahiri (81)Hambali (39)Khalid Shaikh Mohammed (139)Mohammed Haydar Zammar (44)Mohammed Jamal Khalifa (47)Osama Bin Laden (228)Ramzi Bin Al-Shibh (105)Ramzi Yousef (67)Sheikh Omar Abdul-Rahman (57)Victor Bout (23)Wadih El-Hage (45)Zacarias Moussaoui (159)

Al-Qaeda by Region

"Lackawanna Six" (13)Al-Qaeda in Balkans (168)Al-Qaeda in Germany (189)Al-Qaeda in Italy (55)Al-Qaeda in Southeast Asia (149)Al-Qaeda in Spain (121)Islamist Militancy in Chechnya (50)

Specific Alleged Al-Qaeda Linked Attacks or Plots

1993 WTC Bombing (73)1993 Somalia Fighting (13)1995 Bojinka Plot (78)1998 US Embassy Bombings (121)Millennium Bomb Plots (43)2000 USS Cole Bombing (114)2001 Attempted Shoe Bombing (23)2002 Bali Bombings (36)2004 Madrid Train Bombings (82)2005 7/7 London Bombings (87)

Miscellaneous Al-Qaeda Issues

Alleged Al-Qaeda Linked Attacks (89)Alleged Al-Qaeda Media Statements (102)Key Captures and Deaths (124)

Geopolitics and Islamic Militancy

US Dominance (112)Alleged Iraq-Al-Qaeda Links (255)Iraq War Impact on Counterterrorism (83)Israel (61)Pakistan and the ISI (470)Saudi Arabia (249)Terrorism Financing (312)Londonistan - UK Counterterrorism (322)US Intel Links to Islamic Militancy (69)Algerian Militant Collusion (41)Indonesian Militant Collusion (20)Philippine Militant Collusion (74)Yemeni Militant Collusion (47)Other Government-Militant Collusion (23)

Pakistan / ISI: Specific Cases

Pakistani Nukes & Islamic Militancy (37)Pakistani ISI Links to 9/11 (73)Saeed Sheikh (59)Mahmood Ahmed (30)Haven in Pakistan Tribal Region (179)2008 Kabul Indian Embassy Bombing (10)Hunt for Bin Laden in Pakistan (154)

Terrorism Financing: Specific Cases

Al Taqwa Bank (29)Al-Kifah/MAK (54)BCCI (37)BIF (28)BMI and Ptech (21)Bin Laden Family (62)Drugs (71)

'War on Terrorism' Outside Iraq

Afghanistan (299)Drone Use in Pakistan / Afghanistan (49)Destruction of CIA Tapes (92)Escape From Afghanistan (61)High Value Detainees (179)Terror Alerts (50)Counterterrorism Action After 9/11 (352)Counterterrorism Policy/Politics (432)Internal US Security After 9/11 (125)
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