Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: WEDNESDAY, March 3, 1993 TAG: 9303030087
SECTION: BUSINESS PAGE: B8 EDITION: METRO
SOURCE: Associated Press
DATELINE: NEW YORK LENGTH: Medium
HIGHER MAY BE SAFER - IF IT'S NEW
The blast that shook the World Trade Center also rattled some people's confidence in skyscrapers. But experts say the high-rise you work in is probably safer than the house you live in.In most disasters - fires, hurricanes - "I'd rather be in a high-rise than a single-family home," Lynn Beedle, director of the Council on Tall Buildings at Lehigh University, said Tuesday.
And sometimes taller can be safer.
"A 100-story building with state-of-the-art fire systems is probably safer than an older, 20-story building without them," said John Hennessey, a New York engineer.
But the trade center's twin towers are something less than state of the art, and the explosion and fire that closed them last week were something more than an accident.
Sleek, gleaming and huge, the 110-story towers once represented the latest in design. But they were planned in the 1960s, before sprinkler systems and many other features became standard.
The Port Authority of New York and New Jersey, which operates the center, said none of the 350 corporate tenants has expressed a desire to leave. But many of the sooty, scared workers blamed the building as they fled Friday.
Although the towers withstood the blast, their backup systems failed. The explosion disabled emergency lighting, ventilators that would have blown smoke out of the stairways, the fire command center and the public address system.
Instead of automatically returning to lobbies, some elevators got stuck in the towers, trapping people inside.
After the blast, smoke climbed up stairwells and elevators in what's known as a chimney effect. When the doors at the bottom of the towers were opened for evacuation, air rushed into the stairwells and elevator shafts, lifting smoke the way a chimney would over a fireplace.
The Port Authority has acknowledged the need for additional sprinklers, smoke detectors and smoke removers and a bigger command center. It also has promised to evaluate the underground garage where the bomb was planted.
The authority had been warned that the garage was a security risk, but kept it open on the theory that such a large complex needed its own parking.
A high-rise catastrophe "has always been a concern," said Hennessey. "You're putting a lot of people in one place. It's not so much the density, but the ability to evacuate them quickly."
Terrorism complicates the problem, especially when a skyscraper's very size makes it a target.
Designing a safe building "all comes down to assessing risk," said Barry Donaldson, vice president of Tishman Research, a division of a New York construction company. "So we design for the worst hurricane in a 100-year cycle. But we have a statistical history of hurricanes; we don't with terrorists. Nature is more predictable than human nature."
An example: A building can limit the number of entrances to tighten security, but the larger the building, the more entrances are needed. A skyscraper can choke on security.
The trade center explosion is probably the most publicized high-rise catastrophe since a plane crashed into the Empire State Building during World War II. In recent years, there have been serious fires at One Meridian Plaza in Philadelphia, in which three firemen died, and the First Interstate Bank tower in Los Angeles, which killed a worker.
But "The Towering Inferno" has remained fiction, and engineers insist that technology has helped reduce the risks of one. The introduction of sprinklers, for instance, has dramatically reduced high-rise fire deaths around the world.
The future looks even safer. A few new computerized "smart" buildings can give rescuers a picture of where people are in a burning building, where the smoke or fire is and how the emergency systems are working - which fans are blowing, which stairways are lighted.
Nonetheless, technology seems to hold few answers to terrorism.
"Nobody really knows how to deal with it, so how can you design for it?" asks Donaldson.
"The whole point of terrorism is to infiltrate security systems. Does it make sense to design all buildings for all possible terrorists? It gets to be like living in a bunker."