debris damage

The Collapse of a 47-Story Building - WTC7

At 5:20 p.m. on the evening of September 11th, 2001, the Salomon Brothers Building, also known as 7 World Trade Center (WTC7), the northernmost building on the World Trade Center complex, uniformly collapsed in 6.5 seconds. It produced a rubble pile with a radius similar its original dimensions and approximately seven stories tall [1].