About the NIST World Trade Center Investigation

GENESIS OF THIS INVESTIGATION

On August 21, 2002, the National Institute of Standards and Technology (NIST) announced its building and fire safety investigation of the World Trade Center (WTC) disaster.1 This WTC Investigation was then conducted under the authority of the National Construction Safety Team (NCST) Act, which was signed into law on October 1, 2002. A copy of the Public Law is included in AppendixA.

The goals of the investigation of the WTC disaster were:

To investigate the building construction, the materials used, and the technical conditions that contributed to the outcome of the WTC disaster after terrorists flew large jet-fuel laden commercial airliners into the WTC towers.

To serve as the basis for:

Improvements in the way buildings are designed, constructed, maintained, and used;

Improved tools and guidance for industry and safety officials;

Recommended revisions to current codes, standards, and practices; and

Improved public safety

The specific objectives were:

Determine why and how WTC 1 and WTC 2 collapsed following the initial impacts of the aircraft and why and how WTC 7 collapsed;

Determine why the injuries and fatalities were so high or low depending on location, including all technical aspects of fire protection, occupant behavior, evacuation, and emergency response;

Determine what procedures and practices were used in the design, construction, operation, and maintenance of WTC 1, 2, and 7; and

Identify, as specifically as possible, areas in current building and fire codes, standards, and practices that warrant revision...


...NIST found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001. NIST also did not find any evidence that missiles were fired at or hit the towers. Instead, photographs and videos from several angles clearly showed that the collapse initiated at the fire and impact floors and that the collapse progressed from the initiating floors downward, until the dust clouds obscured the view...

http://www.nist.gov/el/disasterstudies/wtc/wtc_about.cfm