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]
September 12, 2001: FEMA Assembles Team to Analyze WTC Collapses, but Investigation Is Severely Hampered
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).
September 14, 2001-April 2002: Engineers Study Flight 77 Crash, But Are Granted Only Limited Access to Crash Site
The American Society of Civil Engineers (ASCE) studies the crash of Flight 77 into the Pentagon and the building’s architectural response to the impact, blast, and subsequent fires. [American Society of Civil Engineers, 1/17/2003] The six-member Pentagon Building Performance Study team is headed by Lead Technical Director Paul F. Mlakar, and also includes Mete A. Sozen. Mlakar and Sozen had previously worked together on the Federal Emergency Management Agency (FEMA) investigation into the Oklahoma City bombing under W. Gene Corley, who is now assigned as FEMA/ASCE’s team leader for the World Trade Center investigation (see September 12, 2001). [Corley et al., 10/1997; Mlakar et al., 1/2003, pp. i 
] Some aspects of the Oklahoma City investigation were controversial. [Guardian, 5/5/2001] Sozen is also tasked with “project conception” for Purdue University’s computer simulation of the Pentagon attack, images from which are also used in the Performance Report, when it is issued later (see January 23, 2003). [Purdue University Department of Computer Science, 9/11/2002] The Building Performance Study team only inspects the Pentagon on two occasions. Team leader Mlakar is granted “limited access” to the site for a week from September 14-21, and on October 4, “controlled access” is granted to the full team, which meets with Corley and inspects the site “for approximately four hours.” All airplane debris has been removed by this time, as well as most of the loose debris from the impact and collapse. Along with interviews and technical information provided by the Pentagon Renovation Project, the photos and data gleaned on these visits are the basis of the team’s analysis of the building’s response to the impact of Flight 77. The study is completed in April 2002, though the report will not be released for another nine months. [Mlakar et al., 1/2003, pp. 1, 18 ]
September 15, 2001 and After: Various Explanations Offered for Pentagon ‘Exit Hole’
Various explanations are offered for the “exit hole” that appeared in an internal wall in the Pentagon following the attack on 9/11 (see May 3, 2002): 
As the hole is near the end of the plane’s trajectory through the building, it is suggested it was made by a piece of the plane. Pentagon Renovation Program spokesman Lee Evey explains on September 15, “the nose of the plane just barely broke through the inside of the C Ring, so it was extending into A-E Drive a little bit.” [US Department of Defense, 9/15/2001] Eleven days later, another military source claims that an engine of the plane was responsible for creating the hole. [MDW News Service, 9/26/2001] Photos, video, and some eyewitness accounts agree on landing gear elements at or near the hole, indicating one of the three sets of landing gear may have been responsible. Sergeant First Class Reginald Powell recalls seeing “a big 8 by 10… hole in the wall. You could see the tire, the landing gear, were just forward of it.” [Marble and Milhiser, 9/2004, pp. 118] The book Debunking 9/11 Myths by Popular Mechanics magazine will say in 2006 that the density of the landing gear means it was “responsible for puncturing the wall in Ring C.” The book cites Air Force Surgeon General Paul Carlton Jr. and Paul Mlakar, lead author of the American Society of Civil Engineers’ (ASCE) Pentagon Building Performance Report, who says “he saw the landing gear with his own eyes.” [Dunbar and Reagan, 2006, pp. 70] A wheel hub is found outside the hole in the A-E Drive service roadway and photographed there. [Jeff Scott and Joe Yoon, 1/21/2007] Another theory put forth in a 2004 National Geographic program is that reverberating shockwaves from the plane’s impact were responsible for the hole. [National Geographic Channel, 2004] Shortly after the attack, rescue workers reportedly “punched a hole” somewhere in the Pentagon “to clean it out,” although there are no sources that say that this was the reason for the hole to the A-E Drive. [US Department of Defense, 9/15/2001] Some accounts refer to the hole as a ‘punch out’ hole, due to the words “punch out” spray painted near it after 9/11. [Mlakar et al., 1/2003, pp. 30 ] However, punch out appears to be a construction term referring to a list of problems to be corrected. In this case it may be a call for assessment of the damage inside. [Home Building Manual, 8/25/2007] French author Thierry Meyssan claims that the unusual nature and shape of the hole indicates it was made by a missile, not an airliner (see Early March 2002). [Meyssan, 2002, pp. 55-63] The 2008 book Firefight: Inside the Battle to Save the Pentagon on 9/11, by Patrick Creed and Rick Newman, will offer a description of the hole and how it was created that is strikingly similar to Meyssan’s earlier observations but without questioning the official account that Flight 77 crashed into the building. In its photo-insert, the book shows a photograph of the exit hole and comments: “The ‘punch-out’ hole blown into a wall where Flight 77 finally came to rest. The hole was created by explosive energy; the plane’s soft aluminum nose and fuselage crumpled the instant it struck the building.” The book also says in its description of the crash, “The 182,000-pound aircraft was morphing into an enormous mass of energy and matter, plowing forward like a horizontal volcanic eruption.” It continues, “As the mass traveled through the building, it began to resemble a shaped charge, a form of explosive that funnels its force into a small, directed area—like a beam of energy—in order to punch holes through armor or other strong material.” [Creed and Newman, 2008, pp. 27]
In addition, the ASCE team’s photo of the hole, and its assessment of the damaged support columns nearest to it, are provided by the FBI, suggesting the bureau has special jurisdiction at the exit hole. [Mlakar et al., 1/2003, pp. 30 ]
October 2002-October 2005: NIST Tries to Estimate Speed of Aircraft Impacting WTC
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]
January 23, 2003: Engineers Release Report on Pentagon Crash
Sixteen months after the attack occurred, the American Society of Civil Engineers (ASCE) releases its Pentagon Building Performance Report on the Pentagon’s architectural response to the impact, blast, and subsequent fires caused by the Flight 77 crash on 9/11. [American Society of Civil Engineers, 1/17/2003] The report, which was finished several months earlier (see September 14, 2001-April 2002), admits “the volume of information concerning the aircraft crash… is rather limited,” but the team is able to give some details of the impact. The report reproduces the five frames of security camera footage made public in 2002 that showed the strike on the Pentagon (see March 7, 2002), seeing in them the approaching aircraft with its top about 20 feet above ground before exploding against and into the building. [Mlakar et al., 1/2003, pp. 14 ] The report notes the plane struck a construction generator and vent structure on the lawn and speculates “portions of the wings might have been separated from the fuselage before the aircraft struck the building.” [Mlakar et al., 1/2003, pp. 35-36 ] The ASCE finds that the plane hit the northern edge of Wedge One of the building—its southwest corner—which had been recently renovated, and that the plane made a 90 foot hole in the outer wall, destroying most ground floor support columns there and the limestone and brick façade between and in front of them. Aircraft debris is then reported to have passed through the building’s three outer rings E, D, and C, following the plane’s trajectory, entering the unrenovated Wedge Two towards the end of the path of destruction. [Mlakar et al., 1/2003, pp. 39 ] The report does not say what caused the much-debated hole in the wall of Ring C, which led on to an internal driveway in the middle of the building. However, in a section on the damage caused by the debris it notes, “There was a hole in the east wall of Ring C, emerging into AE drive,” and a photo of the C Ring hole is included in the report. [Mlakar et al., 1/2003, pp. 28 ]
