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9/11 has led to greater prudence in designing systems that can withstand extreme events, Cornell engineers say

ITHACA, N.Y. -- Thomas O'Rourke illustrates the effects of the World Trade Center destruction with a quote from T.S. Eliot's The Waste Land : "The awful daring of a moment's surrender/ Which an age of prudence can never retract/ By this, and this only, we have existed."

For O'Rourke, the Thomas R. Briggs Professor in Cornell University's School of Civil and Environmental Engineering, the poet's words sum up the tragedy of Sept. 11, 2001: a moment of unforeseen catastrophe that society will pay for with "an age of prudence."

O'Rourke and his Cornell colleagues, Arthur Lembo, research associate in crop and soil sciences, and Linda Nozick, associate professor of civil and environmental engineering, have spent the past two years analyzing the impacts that brought down the twin towers. By studying this and other disasters, O'Rourke says, engineers will be able to give valuable advice to a society still struggling with how best to avoid future tragedies.

The results of the group's study will be a chapter in a book to be published this summer, Impacts of and Human Response to the September 11, 2001 Disasters: What Research Tells Us (Natural Hazards Research and Information Center, 2003).

The book is the result of a National Science Foundation-funded, rapid-response effort to document the effects of the attack on the World Trade Center. The Cornell team focused on the underground infrastructure -- the telephone and electrical systems, water and gas pipes, and subterranean transportation networks -- that had been damaged in the attack.

By analyzing this damage, the team sought to discover ways for urban planners to minimize the effects of future disasters. "We need to understand that terrorism and acts of violence against public works are part of a larger complex of disasters and extreme events that affect our infrastructure," says O'Rourke. "Other extreme events that have similar, if not greater, consequences are earthquakes, hurricanes, tornadoes, floods and severe accidents."

As catastrophic as the World Trade Center damage was, the team found many factors that helped reduce infrastructure disruption. A compartmentalized electrical system (used extensively in New York City but infrequently elsewhere) meant that the blackout in lower Manhattan was confined to a limited number of local distribution systems rather than cascading through a large part of the network. When most telephone calls were blocked in the area, emergency personnel were able to communicate through the Web and e-mail via handheld Blackberry devices, highlighting the importance of wireless e-mail when telephone systems are damaged or disrupted. And a fleet of fireboats pumping water from the Hudson River allowed firefighters to work effectively, even though pressure in water mains, ruptured by fallen debris, dropped to dangerously low levels.

The Cornell team also discovered stories of heroism on the part of New York City's utility workers. On the day of the attack, says Lembo, telephone workers went into the flooded Verizon building just north of World Trade Center 6, risking electrocution in chest-deep water and kerosene to shut off the building's massive circuit breakers by hand. Like the city's police, firefighters and emergency workers, he says, utility workers were running into the World Trade Center complex while other people were running out.

"They accomplished in six days what probably would have been expected to take over 20," says Lembo. "It was Herculean, when you consider that over 70,000 copper wires were severed when steel beams from WTC 2 ripped right through underground cable vaults."

One important outcome of the study, O'Rourke notes, are questions of who should have access to information about infrastructure. Although the researchers had hoped to obtain Geographic Information Systems (GIS) maps of the underground infrastructure, city officials and utility companies considered such information too sensitive to distribute. Also for security reasons, the researchers were unable to obtain clearance to publish some of their results.

The post-9/11 restriction of access to GIS data could be a major setback to engineers and urban planners, says O'Rourke. "This is a major issue for people who care about their society and their government. There's no question, we can't allow information to go out with the openness that we used to," he says. "I just think that we need to work a little harder about coming up with policies about who has access and who doesn't. My concern is that we don't replace what should be an age of prudence with an age of paranoia."

This release was prepared by Cornell graduate student Lissa Harris, a Cornell News Service intern.


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