U.S.

September 11

By Fox News
Published | Updated

Visible from space, a smoke plume rises from Manhattan on Sept. 11, 2001, after two planes crashed into the towers of the World Trade Center. (Photo: NASA)

A commercial plane flies into the World Trade Center in New York City on Sept. 11, 2001, in what would be the worst act of terrorism on U.S. soil. (Photo: AP)

A view of the Empire State Building and the Twin Towers burning after two planes crashed into them as part of the orchestrated terror attacks on Sept. 11, 2001. (Photo: AP)

Lower Manhattan after two planes hit the Twin Towers on Sept. 11, 2001 (Photo: AP)

Two people flee the World Trade Center site on September 11, 2001. (Photo: AP)

A view of the New York City skyline after the terrorist attacks on Sept. 11, 2001. (Photo: AP)

Smoke billows from lower Manhattan after the fall of the Twin Towers on September 11, 2001. (Photo: AP)

Firefighters survey the rubble of the World Trade Center in Lower Manhattan after the devastating terrorist attacks on Sept. 11, 2001. (Photo: AP)

Firefighters survey the rubble of the World Trade Center in New York City after two commercial airliners crashed into the Twin Towers on Sept. 11, 2001. (Photo: AP)

A flag is mounted at the World Trade Center site in Lower Manhattan after the terrorist attacks on Sept. 11, 2001. (Photo: AP) (AP2007)

The Pentagon in Washington, D.C., on Sept. 11, 2001, after a hijacked commercial airliner flew into it during the worst terrorist attacks on U.S. soil. (Photo: AP)

Sept. 11, 2009: The World Trade Center construction site, also known as Ground Zero, in New York City eight years after the tragedy. (Photo: AP)

Wreckage from United Flight 93, which crashed in Shanksville, Pa., killing all 44 passengers aboard.  (Photo: AP)

Wreckage from United Flight 93, which crashed in Shanksville, Pa. after being hijacked. Authorities speculated that the plane was headed for Washington, D.C. (Photo: AP)

A memorial honors a victim of United Flight 93, which crashed in Shanksville, Pa. after being hijacked on September 11, 2001. (Photo: AP)

This flag from a Flight 93 memorial in Shanksville, Pa. reads: "Our nation will eternally honor the heroes of Flight 93."  (Photo: AP)