The fall of the 47-story World Trade Center Building 7 (WTC 7) in New York City late in the afternoon of September 11, 2001, was not a result of fires, according to a draft report by researchers at the University of Alaska Fairbanks (UAF), following a four-year computer modeling study funded by Architects & Engineers for 9/11 Truth.
The UAF team's findings contradict those of the National Institute of Standards and Technology (NIST), an agency of the U.S. Department of Commerce, which concluded in a 2008 report that WTC 7 was the first tall building ever to collapse primarily due to fire. The collapse of WTC 7 has long been the subject of controversy, with critics of the government's account arguing it was brought down in a controlled demolition.
UAF civil engineering professor Leroy Hulsey was the study's principal investigator. Feng Xiao, now an associate professor at Nanjing University of Science and Technology, and Zhili Quan, now a bridge engineer for the South Carolina Department of Transportation, were research assistants and co-authors.
"Our study found that the fires in WTC 7 could not have caused the collapse recorded on video," said Professor Hulsey. "We simulated every plausible scenario, and we found that the series of failures that NIST claimed triggered a progressive collapse of the entire structure could not have occurred. The only thing that could have brought this structure down in the manner observed on 9/11 is the near-simultaneous failure of every column in the building below Floor 17."
The UAF study was funded by Architects & Engineers for 9/11 Truth (AE911Truth), a nonprofit representing more than 3,000 architects and engineers who have signed the organization's petition calling upon Congress to open a new investigation into the destruction of the three World Trade Center towers on 9/11.
The release of the draft report begins a two-month period during which the public is invited to submit comments. The final report will be published later this year. The research team plans to make public by the end of September all of the data used and generated during the study, a decision that contrasts with NIST's withholding of key modeling data on the grounds that releasing it "might jeopardize public safety."