WTC Disaster Shows Value of Evacuation Drills

Despite the tragic nature of the World Trade Center disaster, there was a silver lining: almost everyone who could escape the two doomed buildings did.

World Trade Center, September 11, 2001.

Almost 3,000 people died on September 11, 2001 at the World Trade Center, yet virtually everyone who could escape the buildings did. "When you look at the number of fatalities, it sounds completely crazy to say this, but in terms of how the evacuation proceeded, it was a success," says Dr. Guylène Proulx of the NRC Institute for Research in Construction (NRC-IRC).

Dr. Proulx bases her conclusion on a content analysis of first-person accounts of the evacuation that she and a U.S. colleague have collected. The survivors' stories came from television and radio interviews, newspaper and magazine articles, Web sites-even personal e-mails, which were forwarded to the researchers.

The purpose of their analysis was to determine what cues prompted WTC occupants to evacuate the two buildings and how the evacuations unfolded. "We've studied a number of fires in high-rise and low-rise buildings in Canada to understand what happens when a fire occurs, how people find out about the fire, how they assess the information they receive, and what they do when they realize there is an emergency," says Dr. Proulx. "Our goal is to find ways to reduce how long it takes before people decide to leave."

On September 11, only one-quarter of WTC workers were inside the two towers when disaster struck. "It was Election Day in New York City," she notes. "It was the first day of primary school so many parents were with their kids. Also, many people normally started work at 9:30 a.m. because the trading floor opened at 10:00 - there was no point in getting to work early."

When the first airplane hit Tower One, most of the people inside felt the building shake, says Dr. Proulx. A lot of damage occurred in the first eight floors below where the airplane hit: ceiling tiles, lighting and cables fell down. Raised floors sank. Walls collapsed. Doors jammed in their frames. It was smoky and dusty.

"It seems that people decided very quickly to leave. Yet hardly anybody hit the stairs right away," says Dr. Proulx. "Almost everybody whose accounts we read went back to their office to grab their jacket, their laptop, their cellphone, their palm pilot, whatever - thinking they wouldn't be returning to work for a while" Several people consulted with colleagues. On one floor, about 20 people gathered in a conference room to discuss the situation for about 40 minutes.

"Instead of a panicked response, it was completely the opposite," says Dr. Proulx. "Some people made jokes to encourage each other. In Tower One nobody knew that Tower Two had been attacked. They only realized what was happening when they exited the stairwell in the lobby and saw the level of destruction."

Meanwhile, in Tower Two, many occupants could see balls of flame and debris falling - and people jumping from the higher floors. "Many decided right away to evacuate. They didn't feel threatened, but they wanted to leave the building," says Dr. Proulx.

Shortly before the next airplane struck, an announcement informed the occupants that Tower One had been hit, but Tower Two was secure so people should remain in the building. "When this message was issued, it was perfectly correct," says Dr. Proulx. "The management wanted to make an orderly evacuation. They didn't want occupants to leave the building and be killed by falling debris from Tower One. Fortunately, most people who had started to evacuate just disregarded the message."

When it was over, almost all the victims were from floors above the crash sites. "Right from the start, there was nothing that could have been done differently to save these people," says Dr. Proulx. About 500 rescue workers also died. Below the crash, "76 civilians died. Many of these people may have been inside elevators when the airplanes crashed." Amazingly, almost everyone with a disability was evacuated.

One lesson from this disaster is the importance of being prepared, says Dr. Proulx. "Hardly any fire drills were done in the WTC towers before the 1993 bombing. But after 1993, it was more systematic. Each tenant had an emergency team to make sure everybody leaves on time. Every occupant knew where the stairwells were. Photo-luminescent material was used to light the stairwells, so people could find their way out. All this training paid off on September 11."

Dr. Proulx and her colleague hope to expand on their findings through a new study funded by the U.S. National Institute of Standards and Technology, which will involve actual interviews with WTC survivors. As for future research plans, "we would like to know what impact this event had on occupants who work or live in high-rise structures. How do they perceive their safety now? How would they respond in an emergency? Are people still prepared to live in similar structures? Do we have to redesign buildings to improve evacuation procedures?"

		How would you rate this article?
		12345 1 = not informative5 = very informative Comments: