Loose Change

http://www.debunking911.com/explosions.htm

9/11 Myths and Facts

Myths: Explosives made the twin World Trade Center towers fall. Conspiracy theorists point to the near-perfect vertical fall of the towers and puffs of dust that can be seen ejecting from lower levels of towers as they collapse. They also point out that jet fuel does not burn hot enough to melt the steel that supported each floor of the two towers.

Facts: The WTC twin towers had a very unique load-bearing design that allowed for a wide-open floor plan. This floating-floor structure relied on massive internal support columns at the center of each building. The Boeing 767s that crashed into the buildings critically damaged these internal columns, causing the walls of the buildings to pull inward once the floors started to pancake downward.

The puffs of smoke and dust seen during the collapse of the towers were not the result of demolition explosives. They were merely pockets of trapped air being blown out of windows as the buildings collapsed. If you look at actual demolition footage, you will notice that the explosives go off first, in quick succession up each floor of the structure, and then the building collapses. The WTC puffs of dust can only be seen once the top floors of each building are already in freefall.

So, since the towers survived the plane crashes, could burning jet fuel have caused the buildings to collapse? Jet fuel burns between 1,000 and 1,200 degrees Celsius. Construction-grade steel melts at around 1,500 degrees Celsius. So how did the steel melt? In reality, the steel that supported each floor did not have to melt, it only had to weaken and bend. At 1,000 degrees Celsius, the steel in the impact zones would have retained less than 10 percent of its original strength. In fact, many engineers have a difficult time believing that the buildings remained standing for as long as they did.



http://www.no911conspiracy.com/mythsvsfacts.html