- Author
- Averill, J. D. | Mileti, D. S. | Peacock, R. D. | Kuligowski, E. D. | Groner, N. | Proulx, G. | Reneke, P. A. | Nelson, H. E.
- Title
- Occupant Behavior, Egress, and Emergency Communication. Federal Building and Fire Safety Investigation of the World Trade Center Disaster.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD Colorado Univ., Boulder John Jay Colege National Research Council of Canada, Ottawa, Ontario
- Report
- NIST NCSTAR 1-7, September 2005, 298 p.
- Keywords
- World Trade Center | high rise buildings | building collapse | disasters | fire safety | fire investigations | terrorists | terrorism | building fires | egress | communication networks | evacuation | human behavior
- Identifiers
- World Trade Center (110-story-high) Towers, Manhattan, New York, September 11, 2001; emergency communication; interviews; first-person data collection and analysis methods; September 11, 2001 before the attacks; September 11, 2001, 8:46:30 a.m. Flight 11 crashes into WTC 1; September 11, 2001, 8:47 a.m - 9:02 a.m. Occuapnts react to the Attack on WTC 1; September 11, 2001, 9:02:59 a.m. Flight 175 crashes into WTC2; September 11, 2001, 9:02:59 a.m. - 9:58:59 a.m. 56 critical minutes; September 11, 2001, 9:58:59 a.m. - 10:28:22 a.m. collapse
- Abstract
- 2 on September 11, 2001. Multiple sources of information were collected and analyzed: over 1,000 new interviews with survivors (including 803 telephone interviews, 225 face-to-face interviews, and 5 focus groups); over 700 published interviews; 9-1-1 emergency calls; transcripts of emergency communications, historical building design drawings, memoranda, and calculations; formal complaints filed with the Occupational Safety and Health Administration; and other relevant materials. The egress system, including stairwells and elevators, was described and compared to requirement of both contemporary and current code requirements. This report documents the emergency procedures, both as they were designed to be implemented, as well as how they were actually implemented on September 11, 2001. The population in WTC 1 and WTC 2 on September 11, 2001, at 8:46:30 a.m. was enumerated and described, where the characteristics of the population were relevant to the subsequent evacuation, including training, experience, mobility status, among others. The progress of the evacuation of both towers was described in a quasi-chronological manner from 8:46:30 a.m. when WTC 1 was attacked, until 10:28:22 a.m., when WTC 1 collapsed. Causal models were built to explore the sources of evacuation initiation delay (why people did not immediately start to leave the building) as well as normalized stairwell evacuation time (how long the average occupant spent in the stairwells per floor). Issues identified as contributing to either speeding or aiding the evacuation process were explored. Egress simulations provided context for estimating how long WTC 1 and WTC 2 would have taken to evacuate with different populations, using different models, and subject to different damage to the building.