How people leave a devastated area such as the World Trade Center after the 9/11 attacks is critical to their ability to cope with the risks they face while evacuating, according to new research coauthored by ar professor of planning and public administration at NYU Wagner.

Study: Post-9/11 Evacuation Plans Need to Account for More 'Human' Interruptions.

How people leave a devastated area such as the World Trade Center (WTC) after the 9/11 attacks is critical to their ability to cope with the risks they face while evacuating, thus affecting their chances of survival, according to new research coauthored by NYU Wagner Professor of Planning and Public Administration Rae Zimmerman. “Planning has to be adapted at every level to meet the need for sudden action in a catastrophic situation,” according to the authors.

A survey of WTC evacuees after the 9/11 attacks found when they were leaving the buildings, they stopped to seek information and to connect with co-workers or friends. Approximately one-half of the respondents immediately departed the area and one-half did not evacuate quickly. Almost 73 percent of those who had not left immediately said they “stopped to see what was happening and/or get more information or assistance,” and 53 percent said they “stopped to look for friends or co-workers.” One of the major findings of the survey is that people’s comfort level and ability to take action during uncertain situations is apparently higher in the presence of people they know, a conclusion that emergency planners may increasingly need to take into account.

The paper, entitled “To Leave an Area after Disaster: How Evacuees from the World Trade Center Buildings Left the WTC Area Following the Attacks,” was authored by Professor Zimmerman of New York University’s Wagner Graduate School of Public Service (who heads Wagner's Institute for Civil Infrastructure Systems) and Martin F. Sherman of Loyola University Maryland. The research was funded by the funded by the Centers for Disease Control and Prevention (CDC) through the Association of Schools of Public Health, and presents an analysis of Columbia University’s WTC Evacuation Study (WTCES) data that focused on 1,444 evacuees to evaluate the factors affecting the length of time to initiate and complete the evacuation of occupants from the Towers.

WTC evacuees needed information about escaping not only the buildings, but also the immediate surroundings where falling debris was a constant threat. Information about public transportation options also was a key need.

The study found 28 percent of respondents said they “didn’t know where to go” and 15 percent said they “were not given directions.” According to the researchers, “such communication is important to overcome what is common in some circumstances – denial of the threat.” After deciding to evacuate, about 40 percent gathered up personal items such as keys, laptops, handbags, and files. Those who waited for instructions while still in the building were 1.5 times more likely to have not left the area immediately than those who did. Having undergone fire safety training also led to faster evacuation patterns, the study found.

The study also focused on how people made their way to their initial and ultimate destinations and found those who lived further away tended to quickly evacuate the entire area, sparing them exposure to additional risks. Communicating information about available public transportation is crucial in densely populated areas, but much of the focus has been on communication activity within the Towers prior to and during their collapse, according to the authors.

The article appears in Risk Analysis: An International Journal . The journal is published by the nonprofit Society for Risk Analysis (SRA), a multidisciplinary, interdisciplinary, scholarly, international society that provides an open forum for all those who are interested in risk analysis. Risk analysis is broadly defined to include risk assessment, risk characterization, risk communication, risk management, and policy relating to risk, in the context of risks of concern to individuals, to public and private sector organizations, and to society at a local, regional, national, or global level.

The complete study is available here.

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