On the morning of September 11, 2001, under memorably clear blue skies, two passenger planes bound for the West Coast were hijacked and flown into the World Trade Center’s twin towers in Lower Manhattan. Many sensed correctly at the time that the suicide bombings would forever change the course of American history. Within the hour, another passenger plane smashed into the Pentagon, home to the US Department of Defense, while a fourth plane, headed for an unknown target in Washington, DC, crashed to the ground due to the extraordinary efforts of its passengers who wrested control from the hijackers. The multi-target mission constituted the first and only attack on the mainland by a foreign enemy since the War of 1812; its 2,996 deaths exceeded those suffered at Pearl Harbor.