This report provides technical documentation of how NIST reconstructed the effects of the events on September 11, 2001 on WTC 7. This includes how the fires that followed the impact of debris from the collapse of WTC 1 (the north tower) led to the collapse of WTC 7; an evaluation of the building evacuation and emergency response procedures; what procedures and practices were used in the design, construction, operation, and maintenance of the building; and areas in current building and fire codes, standards, and practices that warrant revision. This report also describes how NIST reached its conclusions. NIST complemented in-house expertise with private sector technical experts; accumulated copious documents, photographs, and videos of the disaster; conducted first-person interviews of building occupants and emergency responders; analyzed the evacuation and emergency response operations in and around WTC 7; performed computer simulations of the behavior of WTC 7 on September 11, 2001; and combined the knowledge gained into a probable collapse sequence.
Citation: NIST NCSTAR - 1-9
Pub Type: NIST Pubs
building evacuation, emergency response, fire safety, structural collapse, tall buildings, World Trade Center