One World Trade Center (WTC 1, or the North Tower) was hit at 8:46 a.m. Eastern time and collapsed at 10:28 a.m. Two World Trade Center (WTC 2, or the South Tower) was hit at 9:03 a.m. and collapsed at 9:59 a.m.
How long did it take for the south tower to collapse?
56 minutes
9:57: The passengers aboard Flight 93 begin a revolt against the hijackers in an attempt to take back the plane. 9:59:00: The South Tower of the World Trade Center collapses, 56 minutes after the impact of Flight 175.
