NIST Continues Progress on WTC Report

Report on Trade Center Collapses Emphasizes Damage to Fireproofing (April 5, 2005, New York Times) reports on the National Institute of Science and Technology's (NIST) April 5, 2005 public progress briefing. Some of the Institutes's findings include:

• Structural damage caused by the impacts of the airplanes in and of themselves was not sufficient to have caused the tower collapses.
• The towers collapsed when the structural frames were further weakened by the fires that followed the plane impacts.
• The structures were rendered more vulnerable to fire when fireproofing was dislodged from the structural steel members by the plane impacts.
• Though jet fuel contributed to the initial fires, the fires were mainly fueled by building contents, and to a lesser extent by aircraft contents.

The article also states that had the towers been full at the time of the attacks (they were each only about 1/3 occupied) roughly 14,000 persons could have died due to the greater time required to evacuate the larger numbers of occupants from the buildings.

Critics Blast Findings of Federal 9/11 Study (April 18, 2005, Engineering News Record) reports on critics who characterize the NIST study as expensive ($16 million) and misguided.

Jon D. Magnusson of Magnusson Klemencic Associates, Seattle, is quoted criticizing NIST for proposing building code changes based on the study of "one building that was unlike any other, for a single vent that had never happened before." Magnusson does not believe the NIST recommendations will lead to actual increases in public safety. Others echo similar concerns, citing a lack of analysis to determine the degree to which recommended safety enhancements can save lives, or characterizing recommendations as based on speculation.

Additional related articles available from ENR include:

• WTC Report Triggers Debate Over Safety (ENR 7/4/2005)
• Recommendations Gain Qualified Support (ENR 7/25/05)
• A New Era for Fire Protection and Life Safety (Architecture Record, 8/2005)

NIST will be publicly releasing its Draft Report and Recommendations on June 23.

More Info:

• Previous articles on Iano's Backfill related to building safety in general and the World Trade Center disaster in particular
• NIST's WTC web site