The official theory of the collapse is essentially a fire theory. So it can not be overemphasized that fire has never caused large steel frame buildings to collapse. Never. Whether before 9/11 or after 9/11 or on 9/11 anywhere else in the world except allegedly New York City. On September 11, 2001 the World Trade Center Twin Towers disintegrated in a manner that scientists say resembled deliberately calculated implosions.The facts open for discussion include: at 5:20 p.m. that same day another building, the 47 story WTC 7, completely collapsed within 70 feet of its footprint in 6.6 seconds.
These three buildings became the first such structures to ever suffer complete collapse due to fire and damage.