Occupant behavior, egress, and emergency communications

Abstract

This report describes the occupant evacuation of World Trade Center (WTC) 1 and WTC 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 stairu'ells 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.

A multi-agent based framework for the simulation of human and social behaviors during emergency evacuations

“…In the case of emergency egress, it is widely recognized that an individual's experiences can significantly impact his/her behavior [2,5,23,24], such as the familiarity of the surroundings, safety procedures, and fire drills. However, "using prior evacuation experience to guide future evacuation decisions, may or may not produce better outcomes" (p. 146) [25]. One observed phenomenon is that most people tend to exit a building following the route that they are most familiar with, and ignore alternate routes.…”

Behavioural science at work for Canada: National Research Council laboratories.

“…NRC-IRC staff investigated the experiences of survivors of the World Trade Center disaster (Averill et al, 2005) and the Cook County Administration Building fire in Chicago (Proulx & Reid, 2006). Such research is the only ethical approach to learn how buildings perform in an emergency, and contributes directly to changes in building and fire codes.…”

Photoluminescent Stairway Installation for Evacuation in Office Buildings

“…Among the differences is the fact that most of the stairways were fully lit for a long time during the 9-11 evacuation. Evacuees surveyed by NIST were asked if they were helped by building features during their evacuation [3]. In WTC1 33% of the evacuees and 17% of those in WTC2 mentioned noticing and being helped by the PLM marking.…”