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WASHINGTON (AP) - The federal official
taking over the investigation of the World Trade Center collapse said Wednesday
he will focus immediately on how to better protect buildings from intense fires
like the ones that brought down the twin towers.
A new report from the Federal Emergency Management Agency and the American Society of Civil Engineers determined that the trade center could have survived the impact of the hijacked 767s.
It fell victim to the intense blaze that set office furniture and paper ablaze like kindling, causing the 110-storey buildings' steel columns to soften and buckle.
The report made general suggestions for potential terrorist targets, such as U.S. Embassies. The probe is now being taken over by the National Institute of Standards and Technology, which will use the report to make changes to building and fire codes.
"It's critical that we understand better the relationship between fire and structural collapse," NIST Director Arden Bement said.
"We believe strongly that the results of such an investigation could lead to major changes in both U.S. building and fire codes and in engineering practice," Bement told the House Science Committee.
Of particular interest to investigators is 7 World Trade Center - the seventh building in the World Trade complex - which is believed to have sustained little structural damage. It collapsed due to fire alone, the first fireproofed steel structure to do so.
Wednesday's hearing was packed with dozens of families of Sept. 11 victims who have formed a group called the Skyscrapers Safety Campaign. Some held up pictures of dead loved ones.
The two-year, $16 million US investigation by NIST is also expected to study ways to harden exit stairways to make them less susceptible to impact and to space them out so one blow might not render them all impassable. Such designs might have allowed occupants on the floors above where the planes hit to have escaped.
NIST will try to find fireproofing that stays attached to critical steel support beams. The report determined that fluffy fireproofing sprayed onto the trade center's steel beams was shaken loose by the impact of the jetliners.
Note : This would probably also be the case in an earthquake situation.
The investigation will also study sprinkler systems, which failed in the trade center after the jetliners sliced supply lines, and fire testing standards critics have called outdated.