!! History Commons Alert, Exciting News

Context of '11:01 a.m.-12:10 p.m., September 11, 2001: Five Shocks Occur at Ground Zero, according to Seismological Data'

This is a scalable context timeline. It contains events related to the event 11:01 a.m.-12:10 p.m., September 11, 2001: Five Shocks Occur at Ground Zero, according to Seismological Data. You can narrow or broaden the context of this timeline by adjusting the zoom level. The lower the scale, the more relevant the items on average will be, while the higher the scale, the less relevant the items, on average, will be.

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

Timeline Tags: Complete 911 Timeline

Steven Stefanakos.Steven Stefanakos. [Source: New York City Police Department.]Recovery workers at Ground Zero search for one of the black boxes from Flight 11 or Flight 175—the planes that crashed into the World Trade Center on 9/11—in locations where a signal from the device has reportedly been picked up, but it is unclear if they find a black box. [Appel, 2009, pp. 281-282] The two “black boxes” carried by all commercial aircraft—the cockpit voice recorder and the flight data recorder—can provide valuable information about why a plane crashed. [CBS News, 2/25/2002; PBS, 2/17/2004] In the week after the 9/11 attacks occur, investigators identify a signal being emitted by one of the black boxes in the WTC debris, according to a report published by the New York State Emergency Management Office (see September 18, 2001). [New York State Emergency Management Office, 9/18/2001, pp. 1 pdf file] The signal is detected by the Federal Aviation Administration (FAA), according to author Anthea Appel. However, while FAA personnel are able to hear the signal, they are unable to pinpoint exactly where it is coming from.
FAA Suggests Two Possible Locations for the Black Box - The FAA initially says it thinks the signal is coming from the corner of Liberty and Church Streets, which border the south and east edges of the WTC site, respectively, and so recovery workers are sent to dig at this location. However, after a few days, it changes its mind and, on September 21, says the signal is coming from Building 5 of the WTC. [Appel, 2009, pp. 281] This nine-story building is located in the northeast corner of the WTC site. [Federal Emergency Management Agency, 5/1/2002, pp. 4-1] The signal is coming from inside or directly under its roof, the FAA says.
Police Officers See No Sign of the Black Box - Lieutenant Delia Mannix of the New York Police Department’s Emergency Service Unit (ESU), who is in charge of the operation to recover the black box, decides the only way to search the roof of Building 5 is to send a team up in a small, waist-high cage known as a “bucket.” Steven Stefanakos and two other ESU officers, who are selected for the task, get into a bucket and a crane lifts them onto the roof of Building 5. Knowing the black box is supposed to be under or embedded in the roof, Stefanakos and the two other officers look around, trying to spot a hole or a dent where the black box could have punctured the roof after being catapulted out of the plane when it crashed into the WTC. The roof, however, appears to be intact.
FAA Staffer Responsible for Locating the Black Box Has Gone Home - Unsure where to search, Stefanakos tries contacting the FAA staffer who is responsible for locating the black box. He tries to reach them three times over his radio but gets no response. Finally, a voice comes over his radio, telling him: “The FAA aren’t here. They went home for the weekend.” Noting that it is only about five o’clock in the afternoon, Stefanakos and his two colleagues are incredulous. As they are being carried down to the ground in the bucket, they comment to each other: “We’ve been workin’ every day for 16 or 17 hours straight with no days off. And here we are, inches away from the black box, and the FAA just get up and leave in the middle of a recovery just because they don’t wanna screw up their weekend!” [Appel, 2009, pp. 281-282] Whether a black box is subsequently retrieved from the roof of Building 5 is unstated. The 9/11 Commission Report will state that the black boxes from the planes that crashed into the WTC “were not found.” [9/11 Commission, 7/24/2004, pp. 456] Furthermore, a report published by the New York City Office of Emergency Management on September 25 will claim that the FAA has in fact been “[u]nable to detect any ‘pinging’ from either ‘black box’” at Ground Zero. [New York City Office of Emergency Management, 9/25/2001, pp. 17-18 pdf file] However, firefighter Nicholas DeMasi, who works extensively in the wreckage of the WTC, will say he helped federal agents recover three black boxes at Ground Zero (see October 2001). [Swanson, 2003, pp. 108; Philadelphia Daily News, 10/28/2004]

Entity Tags: Federal Aviation Administration, New York City Police Department, Delia Mannix, Steven Stefanakos

Timeline Tags: Complete 911 Timeline, 9/11 Timeline

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: Complete 911 Timeline, 9/11 Timeline

Ordering 

Time period


Email Updates

Receive weekly email updates summarizing what contributors have added to the History Commons database

 
Donate

Developing and maintaining this site is very labor intensive. If you find it useful, please give us a hand and donate what you can.
Donate Now

Volunteer

If you would like to help us with this effort, please contact us. We need help with programming (Java, JDO, mysql, and xml), design, networking, and publicity. If you want to contribute information to this site, click the register link at the top of the page, and start contributing.
Contact Us

Creative Commons License Except where otherwise noted, the textual content of each timeline is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike