The World Trade Center Attacks in American History
The World Trade Center Attacks in American History
On September 11, 2001, Americas World Trade Centers was attacked by a faceless enemy, and the people of America stood in shock and mourning. On lookers watched in horror and disbelief, struggling to comprehend what was happening. But at the time there was no answer. All over the country people turned on their televisions and watched as another Bowing 767 crashed into the second tower. The question that’s in the back of my head is why did the building collapse after the planes crashed into the towers? If the engineers and architects had designed the Twin Towers differently could a tragedy like this have been avoided?
The World Trade Center was built around columns that were closely spaced around the perimeter of the towers. Engineers used light weight steel trusses between the elevator and the columns of each floor. The trusses were designed to support the concrete floor and tie together the perimeter to the core of the building. After the planes initial impact nobody thought the impossible was going to happen. Visually you could tell the crash destroyed many floors and took off a significant number of columns. After the planes crashed the jet fuel enflamed the building with temperatures the building could not withstand. The sprinkler systems in buildings such as these are designed to put out office fires, not explosions caused by a plane crash. Eventually, the fire weakened the structure of the skyscraper, and combined with the damage of the impact, caused the floors to collapse one floor after another leaving behind a pile of steel and smoke.
More than 2,200 people died in the 9-11 tragedy because they were trapped above the crashed floors. The stairwells were filled with sheetrock and burning materials. This rubble completely blocked the stairwells and prevented evacuation. This wallboard system was very well engineered for a fire, but not a fire that was caused by the impact of a 767. The initial impact was great enough to collapse this system which would have stopped fire and smoke from spreading to the stairwells. Once theses walls where breached, the victims had no chance. There is also the possibility the breached walls allowed the burning fuel to reach the stairwells.
What’s the answer to this problem? It’s as simple as building stronger walls made of either new steel or...