WTC Never Fireproofed

This is an absolute scandal. Or should be.

Federal investigators studying the collapse of the twin towers on Sept. 11, 2001, say they now believe that the Port Authority of New York and New Jersey, the government agency that built the towers, never performed the fundamental tests needed to determine how their innovative structures would perform in a fire.

The preliminary finding, if it holds up, will undermine decades of public assurances by the Port Authority that the twin towers met or exceeded the requirements of New York City's building code, and therefore would be structurally safe in a large fire. The codes are based on tests of each building component in furnaces that subject the structures, and the fireproofing insulation that protects them, to the harsh conditions of a major fire.

"At this point, we don't know why the tests were not done," said Dr. S. Shyam Sunder, who is leading the eight-month-old investigation at the Building and Fire Research Laboratory at the National Institute of Standards and Technology. But Dr. Sunder added, "To the best of our knowledge, they were not done."

The investigators took great care yesterday to say they were nowhere close to definitively determining how and why the towers collapsed after they were struck by hijacked airliners, and some experts have argued that the buildings were so badly wounded by the impact of the airliners that their ultimate demise was inevitable.

But investigators, speaking at a news conference near ground zero, said their findings about the fire tests were an important development in their examination of one theory for why the buildings collapsed when and how they did: that the huge fires set by burning jet fuel weakened the lightweight floors of the towers, and that the failure of at least several floors in each building set off a chain reaction culminating in the total collapse of the complex.

The investigators have said that it is unclear whether, even if the tests had been done and the buildings been found to have met standards, the lightweight floor structures, called trusses, and the fluffy fireproofing on them could have been expected to withstand the intense fires of Sept. 11.

But the absence of the central tests has robbed the investigators of the ability to even say whether the buildings performed as their designers had specified in their original plans and as the city's codes required of other buildings like them.