World Trade Center leaseholder, Larry Silverstein, admits to giving the order to "pull" building 7. "Pull" is a controlled demolition term for destroying a building.
Building 7 wasn't hit by a plane, yet it collapsed in on itself, with molten steel in it's basement. The only three steel buildings to ever collapse under fire all occured on September 11, and were all owned by the same lease holder, Larry Silverstein.