When were the Twin Towers built and what time did they collapse?

Rare video from ground zero on 9/11

Footage of bodies of those who jumped/fell from the WTC during 9/11. Before the Towers collapsed, an estimated 200 people fell to their deaths from the burning towers, at a speed of almost 150 mph—sufficient to cause instant death, but insufficient to cause unconsciousness during the fall (GRAPHIC)

Buried alive, World Trade Center collapse survivor still carries 9/11 with him today