Sept. 11 Facts and Figures

Nearly a year after the Sept. 11, 2001 terrorist attacks, Time magazine compiled a list of facts and figures about the event.

Here’s a sampling from The Numbers: Remains of a Day:

6 years, 8 months
Time it took to build the World Trade Center, from 1966 to 1973

1 hour, 42 minutes
Time it took to destroy the towers, from the first impact to the second collapse

180 m.p.h.
Speed at which a Boeing 707 could hit the towers but still not destroy them, under the official engineering plan

470 m.p.h., 590 m.p.h.
Estimated flight speeds of the two Boeing 767 jets that hit the towers

0.9
Magnitude of the earthquake-like tremor caused by the impact of American Airlines Flight 11 hitting the north tower

1800°F
Estimated temperature of the fires ignited by the jet fuel

1022°F
Temperature at which steel loses half its strength; it melts at about 2500°F

2.3
Magnitude of the tremor caused by the collapse of the north tower, measured from 21 miles away

To see more, visit Time.