Context of '9:13 a.m. September 11, 2001: Jet Fuel in South Tower Burns Up'

Ramzi Yousef and two other defendants, Abdul Hakim Murad and Wali Khan Amin Shah, are convicted of crimes relating to Operation Bojinka (see January 6, 1995). [CNN, 9/5/1996] In the nearly 6,000-page transcript of the three-month Bojinka trial, there is not a single mention of the “second wave” of Bojinka that closely paralleled the 9/11 plot. Interrogations by Philippine investigator Colonel Rodolfo Mendoza had exposed the details of this plot quite clearly (see January 20, 1995 and February-Early May 1995). However, not only does the FBI not call Mendoza to testify, but his name is not even mentioned in the trial, not even by his assistant, who does testify. “The FBI seemed to be going out of its way to avoid even a hint of the plot that was ultimately carried out on 9/11,” author Peter Lance will later note. [Lance, 2003, pp. 350-51] Murad was extensively tortured during his imprisonment in the Philippines (see After January 6, 1995), and some observers such as law professor Alan Dershowitz will assert that Murad’s case proves the reliability of torture, claiming that Murad’s torture prevented a major disaster. However, others disagree. Law professor Stephanie Athey, in her examination of the case, will write in 2007 that Murad’s torture actually produced little useful information. A computer found in Murad’s apartment held key details of the plot (see January 7-11, 1995 and Spring 1995). CIA agent Michael Scheuer will later say that the information collected from Murad’s apartment, not the information gleaned from Murad’s torture, provided actual useful intelligence. [Vanity Fair, 12/16/2008]

Captain Charles Leidig. [Source: US Navy]Brigadier General Montague Winfield, the deputy director for operations (DDO) in the National Military Command Center (NMCC) at the Pentagon, leaves his post to attend a pre-scheduled meeting, allowing a colleague, who only recently qualified to take over his position, to stand in for him, and not returning to his post until after the terrorist attacks have ended. [9/11 Commission, 7/21/2003 ; 9/11 Commission, 4/29/2004 ; 9/11 Commission, 6/17/2004]
Winfield Attends Air Force-Convened Meeting - Winfield leaves his post to attend what a 9/11 Commission memorandum will call “an unrelated, closed-door personnel meeting convened by the Air Force to discuss the rating of Air Force officers.” [9/11 Commission, 7/21/2003 ] Another Commission memorandum will state that this meeting is a “session for general officers who rated Air Force officers.” It is unclear whether the meeting takes place somewhere in the NMCC or outside the center. The Commission memorandum will only say that it takes place “elsewhere in [Joint Chiefs of Staff] spaces.” At least one of the NMCC’s other qualified DDOs, Brigadier General Norman Seip, is also attending it.
Winfield Asked Colleague to Replace Him on Previous Day - Winfield is temporarily replaced as DDO by Captain Charles Leidig. Leidig only joined the operations directorate of the Joint Chiefs of Staff in July 2001, when he assumed duties as the deputy for Command Center operations. In that, his usual role, he is responsible for the maintenance, operation, and training of watch teams for the NMCC. He qualified to stand in as the DDO in the NMCC about a month ago, in August 2001. The previous afternoon, Winfield asked Leidig to relieve him for a portion of his duty this morning, and Leidig agreed to do so.
Leidig Takes Over as DDO - As arranged, Leidig takes over from Winfield as DDO at 8:30 a.m., allowing Winfield to attend his meeting. Upon arrival at the NMCC, Leidig receives the intelligence and other turn over briefings. After seeing the reports of the plane crashes in New York on television, he will be responsible for convening a significant event conference (see 9:29 a.m.-9:34 a.m. September 11, 2001), which he soon upgrades to an air threat conference (see 9:37 a.m.-9:39 a.m. September 11, 2001). [9/11 Commission, 4/29/2004 ; 9/11 Commission, 6/17/2004 ]
Winfield Does Not Resume Duties until Attacks Are Over - Even though it becomes obvious that a coordinated attack is under way when television shows the second plane hitting the World Trade Center at 9:03 a.m. (see 9:03 a.m. September 11, 2001), Winfield apparently remains in his meeting instead of resuming his duties as DDO (see (Shortly After 9:03 a.m.) September 11, 2001). He will only take over from Leidig as DDO after Flight 93 crashes in Pennsylvania, apparently at around 10:30 a.m. (see (10:30 a.m.) September 11, 2001). [9/11 Commission, 4/29/2004 ; 9/11 Commission, 6/17/2004] In later interviews for television, Winfield will give the impression that he remained in charge of the NMCC throughout the 9/11 attacks, and make no mention of having allowed a stand-in to take his place during this most critical period of time. [CNN, 9/4/2002; ABC News, 9/11/2002]

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 ] 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 ] 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).

Judy Martz. [Source: Publicity photo]Emergency managers from around the US, including Federal Emergency Management Agency (FEMA) Director Joseph Allbaugh and representatives from the emergency management agencies of 47 states, are away from their home states at the time of the terrorist attacks, attending the annual conference of the National Emergency Management Association (NEMA) at a resort in Big Sky, Montana. The main focuses of the event have included the issues of domestic terrorism and weapons of mass destruction. [New York Times, 9/12/2001; State Government News, 10/2001 ] The conference began on September 8, and was originally planned to continue until September 12 (see September 8-11, 2001). [Natural Hazards Observer, 3/2001; National Emergency Management Association, 8/15/2001]
Emergency Managers Learn of Attacks - At 9:00 a.m., conference attendees are scheduled to participate in a series of sessions on domestic preparedness, which has been a key topic for NEMA over the past three years. [National Emergency Management Association, 8/15/2001; State Government News, 10/2001 ] According to the New York Times, “One of the day’s main seminar topics was how to prepare for terrorist attacks.” [New York Times, 9/12/2001] However, numerous pagers go off as officials are notified of the events in New York. By the time officials gather around the television in the resort’s bar to see what is happening, the second plane has hit the World Trade Center (see 9:03 a.m. September 11, 2001) and the nature of the emergency is obvious. [Stateline (.org), 9/10/2002]
Emergency Managers Respond to Attacks - After the emergency managers at the conference see the coverage of the attacks on television, they “automatically organized themselves into particular groups to focus on transportation issues or to capture information,” Trina Hembree, the executive director of NEMA, will later recall. [Stateline (.org), 10/11/2001] The emergency managers, along with federal personnel and private-sector members, go about coordinating their jurisdictions’ responses to the attacks from the resort. Hotel employees add phone lines and equipment so as to enable communication and the tracking of events. A 24-hour emergency operations center is set up, and teams are organized to address specific areas, such as transportation and medical needs. The emergency managers monitor events and stay in contact with their agencies by phone, and also attend briefings at the resort, where they are updated on the national situation. [State Government News, 10/2001 ]
State of Emergency Declared in Montana - Partly due to concerns over the safety of the emergency management officials at the conference, Montana Governor Judy Martz declares a state of emergency. [Stateline (.org), 9/13/2001] Furthermore, roads to the Big Sky resort are closed, and security for the resort is provided by the local sheriff’s department and volunteer fire department, the Montana Highway Patrol, the Montana National Guard, and the FBI.
Arrangements Made to Fly Key Officials Home - The conference’s organizers arrange for military aircraft to fly state emergency management leaders back to their capitals. [New York Times, 9/12/2001; State Government News, 10/2001 ] Allbaugh and officials from several states that are directly involved in the attacks are flown home throughout the day (see (After 11:00 a.m.) September 11, 2001, (After 11:00 a.m.) September 11, 2001, and (After 4:30 p.m.) September 11, 2001), but others at the conference have to drive long distances back to their states.
Emergency Managers 'Not Where They Wanted to Be' - As one news report will later describe, when the attacks occur, “emergency managers were not where they wanted to be.” FEMA spokesman Mark Wolfson will note the inconvenient timing of the attacks, saying that FEMA officials do not know whether they were timed to catch emergency officials off guard. “That would be speculation,” he says. “But it is something that law enforcement investigators might be looking at.” [Stateline (.org), 9/13/2001; State Government News, 10/2001 ] NEMA is the professional association of state emergency management directors. [Natural Hazards Observer, 3/2001] Hundreds of state emergency management officials, including almost all of the US’s state emergency management directors, and most of the senior FEMA staff are in Montana for its annual conference. [Stateline (.org), 9/13/2001; State Government News, 10/2001 ]

Paul Worcester. [Source: Paul Blackmore / Cape Cod Times]Senior commanders at Otis Air National Guard Base in Cape Cod, Massachusetts, become aware of the attacks on the World Trade Center from television coverage, and one commander then orders the base’s battle staff to assemble. The commanders have just been in the first of the base’s regular Tuesday morning meetings, which ended at 8:55 a.m. They are taking a short break before the next meeting, which is scheduled for 9:00 a.m., and are apparently unaware that a plane has crashed into the WTC.
Wing Commander Sees Burning WTC on Television - One of those in the meeting was Lieutenant Colonel Paul Worcester, the logistics group commander of the 102nd Fighter Wing, which is based at Otis. As Worcester walks past the break room he notices that everyone inside it is fixated on the television. He goes in to find what they are watching and gets his first sight of the coverage of the burning North Tower. Worcester finds it odd that a plane could have hit the WTC, and thinks to himself: “On such a clear day, planes don’t just go astray. That just doesn’t happen.” Although he is aware that the base’s two F-15s that are kept on alert have been scrambled in response to a suspected hijacking (see 8:46 a.m. September 11, 2001), he does not connect this with what he is seeing on television.
Commanders See Second Attack - Worcester is joined in the break room by more of the senior commanders. They watch as the live television coverage shows Flight 175 crashing into the South Tower (see 9:03 a.m. September 11, 2001), and all of them then realize that America is under attack. One commander immediately shouts out, “We need to go to battle staff!” The senior commanders disperse and head toward the adjacent operations building, where they will reconvene in the battle cab of the installation operations center (see Shortly After 9:03 a.m. September 11, 2001). A voice sounds out over the base’s loudspeakers: “The commander has ordered the 102nd core battle staff to assemble. Please report to the operations building immediately.”
Unit Mobilizes for War - Subsequently, as author Lynn Spencer will describe: “Under the leadership of the [102nd Fighter] Wing commander, the various subordinate group commanders cross-brief on scramble activity, training flight issues, available munitions, personnel available to begin uploading more fighters to combat-ready status, security force increases, and more. In short, they begin to mobilize the wing for war, keeping NEADS [NORAD’s Northeast Air Defense Sector] in the loop on their preparations.” [Spencer, 2008, pp. 87-88, 153-154]
Base Learned of First Hijacking 20 Minutes Earlier - The 102nd Fighter Wing of the Massachusetts Air National Guard, which is based at Otis Air Base, is responsible for protecting the Northeast United States, including New York, Washington, and Boston. Its mission includes defending the region against terrorist attacks. [Cape Cod Times, 9/12/2001; Cape Cod Times, 9/12/2001] On a typical day, it has about a dozen pilots on duty. [Cape Cod Times, 9/15/2001] It is equipped with 18 F-15 fighter jets, two of which are kept on 24-hour alert, ready to be in the air within five minutes of being called upon. [Boston Globe, 9/15/2001; Cape Cod Times, 9/21/2001] These were the two jets that launched at 8:46 a.m. in response to the hijacking of Flight 11. [9/11 Commission, 7/24/2004, pp. 20] The base was notified about this first hijacking shortly after 8:34 a.m. (see (8:36 a.m.-8:41) September 11, 2001). [Spencer, 2008, pp. 27-28] Why the senior commanders did not initiate their crisis response at that time is unclear.

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).

A special radio transmitter that is carried by aircraft and designed to go off automatically if a plane crashes is activated in the New York area, several minutes before Flight 175 hits the World Trade Center. David Bottiglia, an air traffic controller at the FAA’s New York Center, receives information from one of the aircraft he is monitoring. A few seconds before 8:59 a.m., the pilot of US Airways Flight 583 tells him, “I hate to keep burdening you with this stuff, but now we’re picking up another ELT on 21.5.” [Federal Aviation Administration, 9/11/2001, pp. 37 ; 9/11 Commission, 10/1/2003 ; 9/11 Commission, 2004] An “ELT” is an emergency locator transmitter, a device carried on most general aviation aircraft in the US that is designed to automatically begin transmitting a distress signal if a plane should crash, so as to help search and rescue attempts at locating the downed aircraft. [Federal Aviation Administration, 3/23/1990; US Department of the Army, 8/12/2008, pp. E-6 ; Aircraft Owners and Pilots Association, 1/22/2009] “21.5” refers to the emergency frequency of 121.5 megahertz that ELTs transmit their distress signals on. [Aircraft Electronics Association, 2009, pp. 36 ] While the pilot’s information would mean an ELT is activated at around 8:58 a.m., Flight 175 will crash into the WTC several minutes later, at 9:03 a.m. and 11 seconds (see 9:03 a.m. September 11, 2001). [9/11 Commission, 7/24/2004, pp. 8] And yet there are no reports of an ELT going off at the time of the crash itself. The pilot of Flight 583 earlier on informed Bottiglia of another ELT signal, which had been transmitted shortly before Flight 11 hit the WTC (see 8:44 a.m. September 11, 2001). [New York Times, 10/16/2001; 9/11 Commission, 10/1/2003 ]

Brian Sweeney, a passenger on Flight 175, calls his parents in Spencer, Massachusetts, and tells his mother that his flight has been hijacked and that the passengers are considering storming the cockpit to gain control of the plane. [MetroWest Daily News, 9/12/2001; 9/11 Commission, 8/26/2004, pp. 22 ] Sweeney has just attempted to call his wife, Julie Sweeney, but she was not at home, so he left a message on the answering machine (see 8:59 a.m. September 11, 2001). [Los Angeles Times, 9/17/2001; 9/11 Commission, 7/24/2004, pp. 8]
Sweeney Says He Is on a Hijacked Plane - He now speaks with his mother, Louise Sweeney, saying: “Mom, it’s Brian. I’m on a hijacked plane and it doesn’t look good. I called to say I love you and I love my family.” [Federal Bureau of Investigation, 3/24/2004 ] The call is mostly personal in nature, but Sweeney says of the hijackers, “I don’t know who they are.” [Federal Bureau of Investigation, 9/11/2001] Sweeney’s wife will later tell the New York Daily News that he does, however, tell his mother that the hijackers are Middle Eastern. [New York Daily News, 3/9/2004]
Passengers Thinking of Fighting Back - Sweeney also says that passengers on Flight 175 are considering fighting back against the hijackers. [USA Today, 7/22/2004; 9/11 Commission, 7/24/2004, pp. 8] He says they are thinking of storming the plane’s cockpit. [Federal Bureau of Investigation, 9/11/2001] According to Sweeney’s wife, Sweeney tells his mother, “I might have to hang up quickly, we’re going to try to do something about this,” to which his mother replies: “Okay. Do what you have to do.” Sweeney flew an F-14 fighter jet in the 1991 Gulf War and was a US Navy flight instructor in Miramar, California, but he is now working as an aeronautics consultant for Brandes Associates, a Defense Department contractor. [New York Daily News, 3/9/2004; CNN, 3/10/2004] He is 6-foot-2 and weighs 225 pounds. [Washington Post, 9/16/2001] His wife will say he “could literally kill somebody with a twist of the neck. We could see him trying to do something about [the hijacking].” [New York Daily News, 3/9/2004]
Sweeney Refers to Psychic Television Show - Louise Sweeney asks her son where he is, and he says he believes his plane is flying somewhere over Ohio. [Federal Bureau of Investigation, 3/24/2004 ; 9/11 Commission, 8/26/2004, pp. 22 ] Sweeney says that “they [presumably the hijackers] are coming back.” [Federal Bureau of Investigation, 9/11/2001] He concludes the call by telling his mother: “Remember Crossing Over. Don’t forget Crossing Over.” Louise Sweeney will explain to the FBI that her son is “a very spiritual person who always believed that there was a life after death.” He is much interested in the television show Crossing Over with John Edward, in which the host supposedly communicates with the dead. Louise Sweeney believes her son is trying to comfort her with these words, letting her know he believes they will meet again in the next life.
Sweeney Speaks Quietly and Calmly - According to Louise Sweeney, her son’s voice sounds different to how it normally does. Whereas his usual tone is “effervescent,” during the call it is quiet and very calm, and she will later reflect that he sounds “p_ssed off.” She can hear no loud noises or commotion in the background. [Federal Bureau of Investigation, 3/24/2004 ] The call lasts 60 seconds. [9/11 Commission, 5/13/2004 ] Immediately after it ends, Louise Sweeney turns on her television and sees Flight 175 crashing into the World Trade Center (see 9:03 a.m. September 11, 2001). [Federal Bureau of Investigation, 9/11/2001; 9/11 Commission, 8/26/2004, pp. 22 ]
Conflicting Accounts of What Type of Phone Sweeney Uses - When Sweeney’s mother and his brother, John Sweeney, talk to the FBI over the phone later this morning, they will say Brian Sweeney made the call “from his cell phone.” [Federal Bureau of Investigation, 9/11/2001] Louise Sweeney will tell the FBI later in the day that her son called her “possibly from his cell phone.” [Federal Bureau of Investigation, 9/11/2001] But according to evidence prepared for the 2006 trial of Zacarias Moussaoui, the call is made using an Airfone, not a cell phone. Although Sweeney was originally assigned to seat 15A of the plane, he makes the call from row 31AB. [9/11 Commission, 5/13/2004 ; 9/11 Commission, 8/26/2004, pp. 90 ; US District Court for the Eastern District of Virginia, Alexandria Division, 7/31/2006]

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 ] 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 ] 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).

The second plane hitting the World Trade Center (see 9:03 a.m. September 11, 2001) causes internal alarms to go off in WTC Building 7, located just a few hundred feet away from the Twin Towers. The alarms warn there is no water pressure and that the building’s emergency power generator has been activated. Office of Emergency Management (OEM) staff, based in Building 7, immediately request air security over New York. They are told that federal support is on its way, but the Federal Aviation Administration instructs them to use NYPD and Port Authority Police Department air assets to clear the airspace around the WTC. They are also warned that the Kennedy Airport control tower is reporting an unaccounted for plane heading towards New York. A report by the Mineta Transportation Institute will claim that this plane is Flight 93, which later crashes in Pennsylvania. [Jenkins and Edwards-Winslow, 9/2003, pp. 16] However, Flight 93 is still flying west at this time, and only reverses course and heads towards Washington at around 9:36 a.m. (see (9:36 a.m.) September 11, 2001). According to at least one person at the scene, WTC 7 is evacuated around this time due to the reports of this incoming third plane (see (9:03 a.m.) September 11, 2001). [Jems And FireRescue Supplement, 3/2002, pp. 68 ]

Laura Bush, the president’s wife, leaves the White House in her limousine, on her way to Capitol Hill where she is scheduled to testify before a Congressional committee, but she is unaware that a second plane has crashed into the World Trade Center. [Us Weekly, 10/15/2001; National Journal, 8/31/2002; Bush, 2010, pp. 198] Bush is set to appear before the Senate Committee on Health, Education, Labor, and Pensions, where she will talk about early childhood education. [CNN, 9/12/2001; CNN, 9/11/2002] She was informed of the first crash at the WTC by her lead Secret Service agent as she was getting into her limousine (see (8:55 a.m.) September 11, 2001).
First Lady Unaware of Second Crash - The limousine leaves the White House at 9:07 a.m., according to Noelia Rodriguez, the first lady’s press secretary. [National Journal, 8/31/2002] The second aircraft, Flight 175, hit the WTC four minutes earlier (see 9:03 a.m. September 11, 2001). [9/11 Commission, 7/24/2004, pp. 8] However, Bush and those with her in the limousine are unaware of this. [Bush, 2010, pp. 197-198]
First Lady Thinks about Canceling Hearing - Nevertheless, Bush already thinks the Senate hearing she is on her way to should perhaps be canceled, because New York Senator Hillary Clinton is on the education committee and is therefore supposed to attend. Bush will comment, “Even after the first [crash], when I thought it was just an accident, I thought we probably should cancel, because Mrs. Clinton was on the committee and she’s from New York, and she’d probably want to rush home at that time.” [USA Today, 9/10/2001; Gerhart, 2004, pp. 162] All the same, Bush continues with the two-mile journey from the White House to Capitol Hill. She will learn of the second crash, and realize this is a terrorist attack, shortly before arriving at the Russell Senate Office Building, where the hearing is set to take place (see (9:14 a.m.) September 11, 2001).
Secret Service Allows Bush to Head to Event - Members of Bush’s Secret Service detail apparently raise no objection to Bush going ahead with her trip to Capitol Hill. [CNN, 9/11/2002; Gerhart, 2004, pp. 162; Bush, 2010, pp. 198] The Secret Service is responsible for protecting the first lady, and she is considered to be one of the nation’s “most visible targets.” [US Department of the Treasury, 5/8/2001; Office of Management and Budget, 7/2001, pp. 82 ] The agency’s mission includes keeping her “in sight and out of harm’s way,” according to a book about the Secret Service by author Philip Melanson. [Melanson, 2002, pp. 273] And, as one of the Secret Service’s “permanent protectees,” the first lady, like the president, has a detail of special agents assigned to her. [United States Secret Service, 2002] Bush currently travels with four Secret Service agents and two Secret Service cars. [Kessler, 2006, pp. 136; Kessler, 2009, pp. 181] However, the Secret Service will only take her away from Capitol Hill to a “secure location”—actually the agency’s headquarters—after the terrorist attacks have ended (see (10:10 a.m.-10:55 a.m.) September 11, 2001). [Associated Press, 9/11/2001; National Journal, 8/31/2002; Kessler, 2006, pp. 136]

Vice President Dick Cheney goes from his White House office to the Presidential Emergency Operations Center (PEOC), a bunker below the East Wing of the White House, at about this time, according to counterterrorism “tsar” Richard Clarke and others. There is no video link between response centers in the East and West Wings, but a secure telephone line is used instead. [New York Times, 9/16/2001; Daily Telegraph, 12/16/2001; ABC News, 9/14/2002; Clarke, 2004, pp. 3-4]
Cheney Leaves Office 'Just after 9 a.m.' - One eyewitness, David Bohrer, a White House photographer, will later say Cheney is taken to the PEOC by two or three Secret Service agents just after 9:00 a.m. [ABC News, 9/14/2002] Another eyewitness, President Bush’s personal secretary, Ashley Estes, will recall seeing Secret Service agents running down the hall, carrying Cheney along, just after she saw the second plane hit the World Trade Center on live television at 9:03 a.m. (see 9:03 a.m. September 11, 2001). [White House, 8/29/2002] White House adviser Karl Rove, who is with the president in Florida, will appear to corroborate this account, later telling NBC News that when Bush tries phoning Cheney at around 9:16 a.m., he is unable to contact him because “the vice president was being… grabbed by a Secret Service agent and moved to the bunker” (see (9:16 a.m.-9:29 a.m.) September 11, 2001). [MSNBC, 9/11/2002] And Transportation Secretary Norman Mineta will say that when he arrives at the PEOC, at around 9:20 a.m.-9:27 a.m., Cheney is already there (see (Between 9:20 a.m. and 9:27 a.m.) September 11, 2001). [MSNBC, 9/11/2002; 9/11 Commission, 5/23/2003; Academy of Achievement, 6/3/2006]
Cheney Leaves Office 'Just before 9:36' - However, there will be a second account claiming that Cheney does not leave his office until sometime after 9:30 a.m. (The 9/11 Commission will say he is evacuated “just before 9:36.”) In this account, Secret Service agents burst into Cheney’s office. They carry him under his arms—nearly lifting him off the ground—and propel him down the steps into the White House basement and through a long tunnel toward the underground bunker. [New York Times, 10/16/2001; Newsweek, 12/31/2001; Washington Post, 1/27/2002; BBC, 9/1/2002; MSNBC, 9/11/2002; 9/11 Commission, 6/17/2004] According to journalist and author Stephen Hayes, it takes “[l]ess than a minute” for the Secret Service agents to escort Cheney from his office down to the secure tunnel leading to the PEOC. [Hayes, 2007, pp. 335] Although its specifications are highly classified, two sources will tell journalist and author Barton Gellman that the PEOC is located two floors below ground. [Gellman, 2008, pp. 420]
Arrives at PEOC 'Shortly before 10:00' - Despite admitting that there “is conflicting evidence about when the vice president arrived” in the PEOC, the 9/11 Commission will conclude that the “vice president arrived in the room shortly before 10:00, perhaps at 9:58.” [9/11 Commission, 7/24/2004, pp. 40] In addition to the eyewitness accounts of Clarke, Mineta, and Bohrer, several accounts will claim that Cheney is in the bunker when he is told Flight 77 is 50 miles away from Washington, at about 9:26 a.m. (see (9:26 a.m.) September 11, 2001). This further supports the claims of Cheney going to the PEOC earlier on, rather than after 9:30.

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).

Noelia Rodríguez. [Source: Harvard University]Laura Bush, the president’s wife, is told that a second plane has crashed into the World Trade Center and realizes this is a terrorist attack while she is being driven from the White House to Capitol Hill, where she is scheduled to testify before a Congressional committee. [Us Weekly, 10/15/2001; CNN, 9/11/2002; Bush, 2010, pp. 197-198] Bush is set to appear before the Senate Committee on Health, Education, Labor, and Pensions at 10:00 a.m., where she will talk about early childhood education. [USA Today, 9/10/2001; CNN, 9/12/2001; CNN, 9/11/2002] Her lead Secret Service agent informed her of the first crash at the WTC as she was getting into her limousine, outside the White House, but she’d thought the crash was an accident (see (8:55 a.m.) September 11, 2001). [National Journal, 8/31/2002; Gerhart, 2004, pp. 162]
First Lady Told of Second Crash, Knows It Is Terrorism - The Secret Service agents traveling with Bush now tell the first lady about the second crash at the WTC while her limousine is driving up Pennsylvania Avenue, approaching Capitol Hill. “The car fell silent; we sat in mute disbelief,” Bush will later recall. “One plane might be a strange accident; two planes were clearly an attack.” She will note, “We knew then that it was terrorism.” [CNN, 9/11/2002; Bush, 2010, pp. 198]
Members of First Lady's Staff Learn of Crash - Members of Bush’s staff also learn about the second crash around this time, while they are on their way to Capitol Hill. Ashleigh Adams, the first lady’s deputy press secretary, learns of it while traveling in the press van. “It must have been only a couple of minutes after we departed the White House,” Adams will recall, “that the reporters’ and photographers’ pagers and cell phones started to go off, and someone shouted to me, ‘Ashleigh, the second Twin Tower was hit.’” Adams calls Noelia Rodriguez, the first lady’s press secretary, who is traveling in the staff van, and tells her the news. After Rodriguez arrives on Capitol Hill, she will jump out of the staff van, run to Bush’s limousine, and get inside. But she will find that the first lady has already been informed of the second crash. [National Journal, 8/31/2002]
First Lady Learns of Crash 11 Minutes after It Occurs - Bush will recall that she arrives at the Russell Senate Office Building, where the hearing she is set to attend is supposed to take place, two minutes after she is told about the second crash, at 9:16 a.m., meaning she learns of the crash at 9:14 a.m. [Bush, 2010, pp. 198] This is 11 minutes after the second plane, Flight 175, hit the WTC (see 9:03 a.m. September 11, 2001). [9/11 Commission, 7/24/2004, pp. 8]

Brian Wilson. [Source: Publicity photo]There is apparently no increase in the level of security at the Capitol building in Washington, DC, even though First Lady Laura Bush has arrived at the nearby Russell Senate Office Building and more than 10 minutes have passed since a second plane hit the World Trade Center. [Gilbert et al., 2002, pp. 64; 9/11 Commission, 7/24/2004, pp. 8; Bush, 2010, pp. 198] At 9:16 a.m., Bush arrived at the Russell Senate Office Building, located just north of the Capitol building, where she was scheduled to testify before a Senate committee at 10:00 a.m. [USA Today, 9/10/2001; CNN, 9/12/2001; Bush, 2010, pp. 198]
Reporter Sees No Signs of Increased Security - The first lady is considered one of the nation’s “most visible targets,” and, as one of the Secret Service’s “permanent protectees,” like the president, she has a detail of special agents assigned to her. [US Department of the Treasury, 5/8/2001; Office of Management and Budget, 7/2001, pp. 82 ; United States Secret Service, 2002] And yet, even though Bush has arrived on Capitol Hill, and over 10 minutes have passed since the second aircraft hit the WTC (see 9:03 a.m. September 11, 2001), there is apparently no increase in the level of security at the Capitol building. Fox News correspondent Brian Wilson will later recall that when reporting from the Capitol building around this time, he is “talking about the first lady being in the Capitol and saying that I had not seen any signs of tighter security in the building.”
Reporter Surprised at Plan to Hold a Photo Op - Wilson is also surprised that, although the Senate hearing Bush was scheduled to attend has been canceled, the first lady is still going to make a public appearance. He will comment that “they were (incredibly) trying to set up a brief photo opportunity.” [Gilbert et al., 2002, pp. 64; 9/11 Commission, 7/24/2004, pp. 8] (Wilson is presumably referring to Laura Bush’s appearance before reporters and cameras alongside Senators Edward Kennedy (D-MA) and Judd Gregg (R-NH), which takes place at 9:41 a.m. (see 9:41 a.m. September 11, 2001). [Associated Press, 9/11/2001; CNN, 9/11/2001; Bush, 2010, pp. 199] )
Capitol Evacuated Later On - The Capitol building will only be evacuated at 9:48 a.m., apparently in response to reports of a plane heading toward it (see 9:48 a.m. September 11, 2001). [Associated Press, 9/11/2001; Associated Press, 8/21/2002; CNN, 9/11/2006] The first lady will only be taken away from the Russell Office Building to a “secure location” by members of the Secret Service at 10:10 a.m. (see (10:10 a.m.-10:55 a.m.) September 11, 2001). [Associated Press, 9/11/2001; National Journal, 8/31/2002; Bush, 2010, pp. 200]

Stacia Rountree. [Source: Vanity Fair]Colin Scoggins, the military liaison at the FAA’s Boston Center, contacts NORAD’s Northeast Air Defense Sector (NEADS) and incorrectly notifies it that another aircraft, Delta Air Lines Flight 1989, is a possible hijacking. [9/11 Commission, 2004; Vanity Fair, 8/1/2006] Boston Center previously called NEADS at 9:27 and said that Delta 1989 was missing (see 9:27 a.m. September 11, 2001). [North American Aerospace Defense Command, 9/11/2001; 9/11 Commission, 5/23/2003]
NEADS Technicians Respond - At NEADS, Stacia Rountree, the ID technician who takes Scoggins’s call, announces to her colleagues: “Delta ‘89, that’s the hijack. They think it’s possible hijack.… South of Cleveland.” The plane’s transponder is still on, and she adds, “We have a code on him now.” Rountree’s team leader, Master Sergeant Maureen Dooley, instructs: “Pick it up! Find it!” The NEADS technicians quickly locate Delta 1989 on their radar screens, just south of Toledo, Ohio, and start alerting other FAA centers to it. [Vanity Fair, 8/1/2006; Spencer, 2008, pp. 177] NEADS mission crew commander Major Kevin Nasypany will be notified by his staff of the suspected hijacking at about 9:41 or 9:42 a.m. [9/11 Commission, 1/22/2004 ] NEADS never loses track of Delta 1989. It will follow it on radar as it reverses course over Toledo, heads east, and then lands in Cleveland (see (10:18 a.m.) September 11, 2001). [9/11 Commission, 7/24/2004, pp. 28] It will order Air National Guard fighter jets from Selfridge and Toledo to intercept the flight (see (9:55 a.m.) September 11, 2001 and 10:01 a.m. September 11, 2001). [Spencer, 2008, pp. 178-179] But it will soon learn that Delta 1989 is not in fact hijacked. [9/11 Commission, 7/24/2004, pp. 28]
Cleveland Center, Not Boston, Handling Delta 1989 - Although Boston Center notifies NEADS of the suspected hijacking, Delta 1989 is in fact being handled by the FAA’s Cleveland Center. [USA Today, 8/13/2002; 9/11 Commission, 7/24/2004, pp. 10-12] Cleveland Center air traffic controllers suspected that Delta 1989 had been hijacked at around 9:30 a.m. (see (9:28 a.m.-9:33 a.m.) September 11, 2001), but apparently only informed the FAA’s Command Center, and not NEADS, of this. [USA Today, 8/13/2002] To explain why Boston Center alerts NEADS to the flight, the 9/11 Commission will later comment that, “Remembering the ‘we have some planes’ remark” (see 8:24 a.m. September 11, 2001), the Boston Center simply “guessed that Delta 1989 might also be hijacked.”
Similar to First Two Hijacked Planes - Like Flights 11 and 175, the two aircraft that have crashed into the World Trade Center (see 8:46 a.m. September 11, 2001 and 9:03 a.m. September 11, 2001), Delta 1989 took off from Boston’s Logan Airport. [9/11 Commission, 7/24/2004, pp. 27-28] According to the New York Times, it left there at about the same time as Flights 11 and 175 did, meaning around 8:00 to 8:15 a.m. [New York Times, 10/18/2001; 9/11 Commission, 7/24/2004, pp. 32] Like those two aircraft, it is a Boeing 767. [USA Today, 8/13/2002; 9/11 Commission, 7/24/2004, pp. 27-28] But, unlike those flights, its transponder has not been turned off, and so it is still transmitting a beacon code. [9/11 Commission, 7/24/2004, pp. 28; Vanity Fair, 8/1/2006] It is unclear what Delta 1989’s intended destination is. According to some accounts, like Flights 11 and 175 were, it is bound for Los Angeles. [Associated Press, 9/11/2001; New York Times, 10/18/2001; USA Today, 8/13/2002; Arizona Daily Star, 9/24/2007; Spencer, 2008, pp. 167] Other accounts will say that its destination is Las Vegas. [9/11 Commission, 7/24/2004, pp. 28; Vanity Fair, 8/1/2006] Personnel at NEADS are apparently informed that Las Vegas is the intended destination. Around this time, one member of staff there tells her colleagues that the flight is “supposed to go to Vegas.” [North American Aerospace Defense Command, 9/11/2001]
One of Numerous Incorrect Reports - The 9/11 Commission will comment: “During the course of the morning, there were multiple erroneous reports of hijacked aircraft (see (9:09 a.m. and After) September 11, 2001). The report of American 11 heading south was the first (see 9:21 a.m. September 11, 2001); Delta 1989 was the second.” [9/11 Commission, 7/24/2004, pp. 28]

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]

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]

Twenty minutes after the 9/11 attacks in New York (see 8:46 a.m. September 11, 2001 and 9:03 a.m. September 11, 2001) and Washington (see 9:37 a.m. September 11, 2001), a bomb truck is stationed in downtown Oklahoma City, in preparation for any potential bombing related to the 1995 Oklahoma City bombing (see 8:35 a.m. - 9:02 a.m. April 19, 1995). Additionally, an Oklahoma County Sheriff’s Department command post is activated where convicted bombing conspirator Terry Nichols (see September 5, 2001) is being held. [The Oklahoman, 4/2009]

United Airlines issues a press release confirming that Flight 93 has crashed. Flight 93 went down in Pennsylvania shortly after 10:00 a.m. (see (10:06 a.m.) September 11, 2001). The release states: “United Airlines has confirmed one of its flights has crashed near Pittsburgh, Pennsylvania. United Flight 93, a Boeing 757 aircraft, is the flight number involved. The flight originated in Newark and was bound for San Francisco.” The release adds, “United is deeply concerned about a further flight, United Flight 175, a Boeing 767, which was bound from Boston to Los Angeles.” [United Airlines, 9/11/2001] Although Flight 175 hit the World Trade Center at 9:03 (see 9:03 a.m. September 11, 2001), United Airlines will not publicly confirm it has crashed until 11:53 a.m. (see 11:53 a.m. September 11, 2001).

United Airlines finally issues a press release confirming that Flight 175 has crashed, nearly three hours after this aircraft hit the World Trade Center (see 9:03 a.m. September 11, 2001). The release states, “United Airlines has now confirmed that two of its aircraft have crashed.” These include “United Flight 175, a Boeing 767 aircraft, [that] departed from Boston at 7:58 a.m. local time, bound for Los Angeles, with 56 passengers onboard, two pilots and seven flight attendants.” [United Airlines, 9/11/2001] United Airlines previously issued a press release, at 11:17, confirming the crash of Flight 93 (see 11:17 a.m. September 11, 2001), but this had stated that the airline was, at that time, only “deeply concerned” about Flight 175. [United Airlines, 9/11/2001] However, at 9:22, the United Airlines System Operations Control manager had issued an advisory to all the airline’s facilities, stating that Flight 175 had been in an accident in New York (see 9:22 a.m. September 11, 2001). [9/11 Commission, 8/26/2004, pp. 26 ] And Colin Scoggins, the military liaison at the FAA’s Boston Center, will later claim that United confirmed to the center that Flight 175 was down, “within two or three minutes” (see (9:06 a.m.) September 11, 2001). [Vanity Fair, 8/1/2006]

The man in the picture on the left is supposed to be bin Laden in October 2001. The picture on the right is undisputendly bin Laden in December [Source: Reuters]Following the release of a home video in which Osama bin Laden apparently confesses to involvement in 9/11 (see Mid-November 2001), some commentators question its authenticity, as a number of strange facts about the video soon emerge. For example, all previous videos had been made with the consent of bin Laden, and usually released to the Arabic television channel Al Jazeera. This video was supposedly recorded without his knowledge, found in a house in Afghanistan, and then passed to the CIA by an unknown person or group. Experts point out that it would be possible to fake such a video. So many people doubt the video’s authenticity that President Bush soon makes a statement, saying it was “preposterous for anybody to think this tape was doctored. Those who contend it’s a farce or a fake are hoping for the best about an evil man.” [Guardian, 12/15/2001] Some commentators will suggest that the person thought to be bin Laden is not actually the al-Qaeda leader. For example, arabist Kevin Barrett will say that the person in the video is “at least 40 or 50 pounds heavier, and his facial features [are] obviously different.” [Capital Times (Madison), 2/14/2006] The man said to be bin Laden also makes some questionable statements in the video:
“I was thinking that the fire from the gas in the plane would melt the iron structure of the building…” [US Department of Defense, 12/13/2001 ] The jet fuel spilled from the planes burned up about 10 minutes after impact (see 8:57 a.m. September 11, 2001), the towers’ structure did not melt (see September 12, 2001-February 2002), and the towers were not made of iron, but steel. [National Institute of Standards and Technology, 9/2005, pp. 6] Bin Laden had studied civil engineering at university and had experience as a construction contractor. [Burke, 2004, pp. 47; Laden, 2005, pp. xii-xiii] It is unclear why he would think the towers were made of iron.
“We did not reveal the operation to [the brothers who conducted the operation] until they are there and just before they boarded the planes.” [US Department of Defense, 12/13/2001 ] All the hijackers purchased tickets for the 9/11 flights about two weeks in advance (see August 25-September 5, 2001). The six plot leaders had flight training (see July 6-December 19, 2000, (June 28-December 2000), January-February 2001, and May 5 and 10, 2000), and some of the other 13 are thought to have assisted with target surveillance and casing flights (see May 24-August 14, 2001, August 1, 2001, June 2001 and August 2001).
“Those who were trained to fly didn’t know the others. One group of people did not know the other group.” [US Department of Defense, 12/13/2001 ] The opposite is true: the pilots intermingled with the muscle and the teams for the various planes mixed (see April 23-June 29, 2001, April 12-September 7, 2001, and June 27-August 23, 2001).
There are reports that bin Laden had from four to ten look-alike doubles at the time. [Agence France-Presse, 10/7/2001; London Times, 11/19/2001]

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]

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 ] 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 ; National Institute of Standards & Technology, 9/2005, pp. 152-165 ; National Institute of Standards and Technology, 9/2005, pp. 109]

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 ; Engineering News-Record, 10/25/2002; New York Times, 10/29/2002; Engineering News-Record, 11/4/2002; Real Estate Weekly, 4/30/2003]

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]

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]

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]

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 ; National Institute of Standards & Technology, 9/2005, pp. 263-274 ; 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 ]

Former 9/11 Commission co-chair Lee Hamilton. [Source: CBC]Lee Hamilton, the former co-chair of the 9/11 Commission, gives a wide-ranging interview to the CBC about Without Precedent, a book he recently co-authored about his time on the 9/11 Commission (see August 15, 2006). In the interview he discusses the various “conspiracy theories” surrounding the events of 9/11. The interviewer, Evan Solomon, mentions to him a recent Zogby poll (see May 17, 2006) that found that 42% of Americans agreed that “the US government, and its 9/11 Commission, concealed or refused to investigate critical evidence that contradicts the official explanation of September 11th.” Hamilton calls this lack of trust in the Commission’s report “dispiriting,” but attacks the “conspiracy theory people,” saying, “when they make an assertion they do it often on very flimsy evidence.” He addresses some of the various “conspiracy theories” that have been put forward about 9/11:
In order to contradict the allegation that the Twin Towers were brought down deliberately with pre-planted explosives, Hamilton says the WTC collapsed (see 8:57 a.m. September 11, 2001) because “the super-heated jet fuel melted the steel super-structure of these buildings and caused their collapse.” He adds, “There’s a powerful lot of evidence to sustain that point of view, including the pictures of the airplanes flying into the building.”
With regard to the collapse of WTC Building 7 (see (5:20 p.m.) September 11, 2001), which some people claim was also caused by explosives, he argues, “[W]e believe that it was the aftershocks of these two huge buildings in the very near vicinity collapsing. And in the Building 7 case, we think that it was a case of flames setting off a fuel container, which started the fire in Building 7, and that was our theory on Building 7.” However, the interviewer points out that the 9/11 Commission’s final report does not actually mention the collapse of Building 7, and Hamilton says he does not recall whether the Commission made a specific decision to leave it out.
In reply to a question about why the debris of Building 7 were moved quickly from the scene without a thorough investigation, even though nobody died in Building 7 and there was no need for rescue operations there, Hamilton responds, “You can’t answer every question when you conduct an investigation.”
When asked whether Saeed Sheikh sent Mohamed Atta $100,000 for the 9/11 plot (see Early August 2001 and Summer 2001 and before), Hamilton replies, “I don’t know anything about it.” When the interviewer presses him about whether the Commission investigated a possible Pakistani Secret Service (ISI) connection to the attacks, Hamilton replies, “They may have; I do not recall us writing anything about it in the report. We may have but I don’t recall it.”
Asked about Secretary of Transportation Norman Mineta’s claim that Vice President Dick Cheney was in the presidential bunker beneath the White House at 9:20 a.m. on 9/11 (see (Between 9:20 a.m. and 9:27 a.m.) September 11, 2001), almost 40 minutes earlier than the Commission claimed he had arrived there, Hamilton replies, “I do not recall.” When pressed, he expands, “Well, we think that Vice President Cheney entered the bunker shortly before 10 o’clock. And there is a gap of several minutes there, where we do not really know what the Vice President really did. There is the famous phone call between the President and the Vice President. We could find no documentary evidence of that phone call.”
When the interviewer points out that Richard Clarke’s account conflicts with the Commission’s over what time authorization was received from Dick Cheney to shoot down Flight 93 (see (Between 9:45 a.m. and 9:56 a.m.) September 11, 2001 and (Between 10:00 a.m. and 10:15 a.m.) September 11, 2001), Hamilton retorts, “Look, you’ve obviously gone through the report with a fine-toothed comb, you’re raising a lot of questions—I can do the same thing.”
The interviewer also asks Hamilton whether he has any unanswered questions of his own about 9/11. Hamilton’s response is: “I could never figure out why these 19 fellas did what they did. We looked into their backgrounds. In one or two cases, they were apparently happy, well-adjusted, not particularly religious - in one case quite well-to-do, had a girlfriend. We just couldn’t figure out why he did it. I still don’t know.” [Canadian Broadcasting Corporation, 8/21/2006]