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People 'need to be trained' to not delay evacuation

World Trade Centre twin towers

People must be trained not to delay in the evacuation of buildings, a study of the attacks on the World Trade Centre has concluded.

According to data gathered following the events of September 11 2001 in New York, more than 90% of people working in the Twin Towers delayed evacuating to carry out tasks. The research team said important lessons needed to be learned from their findings.

Interviews with 271 survivors found that just 8.6% fled as soon as the alarm was raised. The vast majority sought further information or undertook a range of duties such as saving documents or collecting personal items.

Researchers from the the Universities of Greenwich, Ulster and Liverpool spent three-and-a-half years interviewing former employees at New York's World Trade Centre about the events on the day of the attack.

It was found that congestion on the stairs was the main cause of delay, even though the towers were less than one-third full at the time of the attack. Computer simulations had shown that if working to occupational capacity some 7,592 would have died in the north tower of the World Trade Centre. This was more than five times the recorded death total of 1,462.

HEED database
However, worker's behaviour also added to the delay in evacuating. Researchers found that 91.4% of survivors waited for information or carried out at least one duty before leaving. Some went to the toilet, while others waited to shut down computers, phone their families, or collect items before evacuating.

In so doing the majority delayed their escape by around eight minutes. Some saw their evacuation put back by half an hour, researchers found.

Project director Professor Ed Galea, of the University of Greenwich, said: "To try and reduce occupant response times we need to understand what factors contribute to prolonging people's response to emergency situations.

"We need to train people that when you hear the alarm, you need to get out. It is not important to shut down the computer or save documents."

The respondents' answers have been fed into a High-rise Evacuation Evaluation Database (HEED) aimed at improving the safety of high rise buildings across the world.

The research team added that many of the interviewees had benefited from talking about their experiences. In addition, the researchers donated $5,420 (¿3,081) to the World Trade Centre Survivors' Network in recognition of the help given by participants to the study.

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