Excessive heat from the fire was too much for Trade Center's structure, says a Tufts civil engineering expert

New York [09.12.01] -- For awhile, it looked as if New York's World Trade Center towers would survive the damage caused by the impact of two hijacked airliners on Tuesday morning. But the excessive heat from the burning jet fuel was too much for the massive structures, causing them to collapse -- one after another -- into a towering cloud of debris, said a Tufts structural engineering expert.

   "In my opinion, the fire weakened the connection between the floor system and the columns on the higher floors and caused a couple floors to collapse," Tufts' Masoud Sanayei told the Associated Press on Tuesday.

   According to the Tufts expert, the weight of the collapsed floors at the top of the buildings put tremendous strain on the Trade Center's support columns, which are spaced out every few feet around the towers.

   "The reason why it looked like an implosion -- which is the technique regularly used by construction and demolition workers to take down a skyscraper -- is because it was just that," he said.

   Sanayei said the building just "pancaked" and fell onto itself.

   "The floors are very heavy, made of reinforced concrete, so when one hits the next, they cause a domino effect," he said in the AP article which appeared in newspapers around the world. "It can go all the way down to the first floor."

   In such a case, the loss of life is unavoidable.

   "There is no way anyone can survive this situation," Sanayei said.

Skyline Forever Altered

The towers' collapse will forever change the city, explained a Tufts expert on the New York skyline. Their construction transformed the city's skyline and their collapse has done the same.

   "The loss of the Twin Towers has dramatically transformed of the city's great skyline for the first time in many years," said Tufts' Daniel Abramson, author of the just-published book Skyscraper Rivals. "With no other tall buildings around the Towers, they stood out along with the Empire State Building and the Chrysler Building to define the view of New York."

   The towers were, themselves, small cities within New York, the art history expert said.

   "With the stores, offices and services that were located in both buildings, and the third that fell later, the destruction of the World Trade Center is equal to the destruction of an entire small city unto itself," said Abramson. "Although, thankfully, no people lived there, it represented the size, population and activity of many small American cities."

Images courtesy Associated Press and Reuters