Building 7

Building 7 is a 47-story, steel-framed, fire-protected, high-rise office building located about a football field’s length from the WTC North Tower. It was not hit by a plane and only had isolated pockets of fire in ten floors, it suddenly imploded, coming down neatly and symmetrically at 5:20 pm. 7 hours after the south and north towers collapsed.

http://goo.gl/NwFus5