On September 11, 2001, terrorists hijacked four jets and used
them as weapons in attacks against the United States. They flew
two of the planes into the Twin Towers of the World Trade Center
in New York City. (Click here for a close-up map of New York
City attacks.) They crashed a third plane into the Pentagon,
which houses the Department of Defense, near Washington, D.C.
(Click here for a close-up map of D.C. attacks.) The fourth
plane crashed in a field in Shanksville, Pennsylvania. Officials
believe that the terrorists intended to destroy either the White
House or the U.S. Capitol with that plane. Passengers on the
plane fought the terrorists and prevented them from reaching
their goal.