Steven Stellman - Evacuating damaged and destroyed buildings on 9/11: behavioral and structural barriers

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      Publication Details (including relevant citation   information):

      Groeger, J. L., Stellman, S. D., Kravitt, A., Brackbill, R. M.   28 (6) 556-66-

      Abstract: INTRODUCTION: Evacuation of the World   Trade Center (WTC) twin towers and surrounding buildings damaged   in the September 11, 2001 attacks provides a unique opportunity   to study factors that affect emergency evacuation of high rise   buildings. Problem The goal of this study is to understand the   extent to which structural and behavioral barriers and   limitations of personal mobility affected evacuation by occupants   of affected buildings on September 11, 2001. METHODS: This   analysis included 5,023 civilian, adult enrollees within the   World Trade Center Health Registry who evacuated the two World   Trade Center towers and over 30 other Lower Manhattan buildings   that were damaged or destroyed on September 11, 2001. Multinomial   logistic regression was used to predict total evacuation time   (<30 to </=60 minutes, >1 hour to <2 hours relative   to </=30 minutes) in relation to number of infrastructure   barriers and number of behavioral barriers, adjusted for   demographic and other factors. RESULTS: A higher percentage of   evacuees reported encountering at least one behavioral barrier   (84.9%) than reported at least one infrastructure barrier   (51.9%). This pattern was consistent in all buildings except WTC   1, the first building attacked, where >90% of evacuees   reported encountering both types of barriers. Smoke and poor   lighting were the most frequently-reported structural barriers.   Extreme crowding, lack of communication with officials, and being   surrounded by panicked crowds were the most frequently-reported   behavioral barriers. Multivariate analyses showed evacuation time   to be independently associated with the number of each type of   barrier as well as gender (longer times for women), but not with   the floor from which evacuation began. After adjustment, personal   mobility impairment was not associated with increased evacuation   time. CONCLUSION: Because most high-rise buildings have unique   designs, infrastructure factors tend to be less predictable than   behavioral factors, but both need to be considered in developing   emergency evacuation plans in order to decrease evacuation time   and, consequently, risk of injury and death during an emergency   evacuation.

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