The
September 11 attacks, commonly known as 9/11,e were four coordinated Islamist
suicide terrorist attacks carried out by al-Qaeda against the United States in 2001. That morning, 19 terrorists hijacked four commercial airliners scheduled to travel from the New England and
Mid-Atlantic regions of the East Coast to
California. The hijackers crashed the first two planes into the Twin Towers of the World Trade Center in New York City, two of the world's five tallest buildings at the time, and aimed the next two flights toward targets in or near Washington, D.C., in an attack on the nation's capital. The third team succeeded in striking the Pentagon, the headquarters of the U.S. Department of Defense in Arlington County, Virginia, while the fourth plane went down in rural Pennsylvania during a passenger revolt. The September 11 attacks killed 2,977
people, the deadliest terrorist attack in human history, and instigated the multi-decade global war on terror, fought in Afghanistan, Iraq, and elsewhere.