Minoru Yamasaki, Architect
(from Paul Heyer, Architects on Architecture: New Directions in America. P 194195)
By Lesley Harding
On July 28, 1945, an Army Air Force B-25 crashed into the Empire State Building between the 79th and 80th floors. Fourteen people died. Damage to the building was $1 million, but the structural integrity of the building was not affected.
On Sept. 11, two commercial jets slammed into the twin towers of the World Trade Center and the result was total devastation.
I couldnt believe what I was seeing, says Harold Giles, professor of architecture. I watched as the second plane crashed into the south tower and as it crumbled to the ground. I could still see flames coming out of the north tower but hoped it would stabilize and burn out. It was a real shock when that one came down, too.
I didnt believe anyone would ever think about toppling the towers, let alone pull it off, says James Wight, professor of civil engineering.
These two men sat mesmerized as they watched this architectural and engineering wonder vanish before their eyes. The events of that terrible day are making architects, civil engineers and urban planners think twice about the use of these sky-high structures.
There ought to be a review of the risk analysis on potential disaster scenarios in large buildings and we need to assess the impact of this tragedy in the formulation of our future designs, says Giles. We need to pay more attention as to how we get people into safe areas quickly or out during emergencies. Weve thought about bombs, but no one has ever really accounted for intense heat or the catastrophic action of a plane hitting a building.
The World Trade Center was indeed protected from temperatures as high as 1,000 degrees Fahrenheit. Steel girders on the buildings exterior tube design were clad in fire retardant material but not meant to endure temperatures of close to 2,000 degrees Fahrenheit.
The towers themselves were strong enough to withstand the impact of the planes. It was the searing heat that softened the main steel structure. It became like a wet spaghetti noodle and pancaked the floors on the way down, says Wight.
Nearly 2,000 tons of concrete, flooring, walls and office furniture on each of the 110 floors came crashing down.
Wight thinks this is the result terrorists were hoping for in the 1993 bombing attempt on the same building but their plans were actually thwarted by the crumbling structure. The explosion was in the basement parking structure and three stories of rubble accumulated at the lowest level. These stacks of debris braced the buildings support columns and saved the Center from falling.
The horrific events of Sept. 11, the bombing in 1993 and other man-made and environmental disasters endured by the worlds skyscrapers will be the topics of discussion as engineers, architects and urban planners meet over the next few weeks to discuss the future of design and build of these breathtaking buildings.
I dont think they should rebuild, says Wight. The fact that its been attacked before would just give terrorists another target. Do we really want to put such a large amount of human and monetary capital in one structure? They have already proven that were vulnerable.
But Giles feels the skys the limit. I think they should build another skyscraper there. These buildings have become a token of our progress and engineering achievement. To see something like this wiped off the face of the earth is a different kind of tragedy, separate from the tragic loss of life that we all witnessed. We have the means by which to address this issue.