By the Numbers

65.4

Million air travelers in the U.S. in August 2001, a then-record for one month

July 2004

The month air passenger travel returned to its pre-9/11 peak

300,000

Square feet of underground space that has been constructed at the World Trade Center site for the base of two skyscrapers, a train station, and the Sept. 11 museum

1,362 and 1,368

Feet, height of the World Trade Center towers

100 Feet

Height of 1 World Trade Center (formerly known as Freedom Tower) today

1,776

Feet, the final height of 1 World Trade Center, including antenna, when it opens in April 2013

2.6 million

Square feet of office space the 1 World Trade Center will include (representing just 25 percent of the office space lost in lower Manhattan on 9/11)

725

Minimum increase in fatalities in car crashes in the three months after 9/11 because more people drove instead of flying in the wake of the attacks

Sources: New York Times; Lower Manhattan Development Corporation; Cornell University; federal Bureau of Transportation Statistics