A Critique of the NIST WTC Reports and the Progressive Collapse Theory | Larry Cooper, SE, PE

The tragic destruction of the World Trade Center Twin Towers on September 11, 2001, resulted in the greatest loss of life of any building failure in history, causing the deaths of 2,763 people. The ASCE Journal of Engineering Mechanics published a series of influential papers between 2002 and 2011 putting forth a theory that the Twin Towers’ destruction was a progressive collapse caused by the airplane impact damage and the ensuing fires. Meanwhile, in 2005, the National Institute of Standards and Technology (NIST), an agency of the U.S. Department of Commerce, issued a report concluding that the collapses were indeed caused by the airplane impact damage and ensuing fires. However, NIST limited the scope of its investigation to “collapse initiation” and conducted no analysis to corroborate the ASCE-published theory of why the Twin Towers completely collapsed following the initiating event. This presentation, based on more than 17 years of research by engineers and scientists, provid