UCSD Jacobs School of Engineering University of California San Diego
Pulse Subscribe | Archive | Survey

Forman Williams Advising on Investigation of WORLD TRADE CENTER TOWER FAILURES

Forman Williams

The September 11, 2001 terrorist attack on the World Trade Center towers killed 2,752 people and triggered a massive investigation of how and why the buildings fell. The National Institute of Standards and Technology (NIST) concluded that the impacts damaged core and perimeter columns and concrete-steel trussed floor systems. While most of the jet fuel released in both buildings burned in a few minutes, Jacobs School mechanical engineering professor Forman Williams, an expert on combustion and one of 10 members of an advisory committee working with NIST investigators, said there is no doubt that subsequent fires in the buildings softened the undamaged load-bearing columns and floor systems.

A recently released draft report described the "leading hypothesis" for each collapse, but Williams says the exact chain of events for each may never be known precisely The goal of the investigation is to recommend improvements in the design, construction, maintenance, and use of buildings, particularly high-rises. The final NIST report will be available in April or May 2005.