What was 9/11?

9/11 refers to the coordinated terrorist attacks on the United States carried out by 19 al-Qaeda hijackers on the morning of Tuesday, September 11, 2001, the deadliest foreign attack on American soil in history and the event that defined American foreign policy for the next two decades. Nineteen members of the terrorist network al-Qaeda, founded and led by Saudi exile Osama bin Laden, hijacked four commercial airplanes that morning. American Airlines Flight 11 was crashed into the North Tower of the World Trade Center in New York City at 8:46 a.m. United Airlines Flight 175 struck the South Tower at 9:03 a.m. American Airlines Flight 77 hit the Pentagon outside Washington, D.C. at 9:37 a.m. United Airlines Flight 93, which had been heading toward either the Capitol or the White House, crashed into a field near Shanksville, Pennsylvania at 10:03 a.m. after passengers, having learned by cell phone of the other attacks, stormed the cockpit.

Both World Trade Center towers collapsed within two hours of being struck, the South Tower at 9:59 a.m. and the North Tower at 10:28 a.m., killing thousands of office workers and hundreds of New York firefighters and police officers responding to the scene. The attacks killed 2,977 people from more than 90 countries, plus the 19 hijackers. The dead included 343 New York firefighters, 23 New York police officers, and 37 Port Authority officers. Most victims were American civilians at work in the towers and the Pentagon.

The attacks destroyed both World Trade Center towers, severely damaged the western side of the Pentagon, and brought air travel to a halt nationwide. The Federal Aviation Administration grounded all civilian flights for the first time in American history. The economy lost an estimated 100 billion dollars in the immediate aftermath, and the New York Stock Exchange did not reopen for six trading days.

President George W. Bush, who had been reading to schoolchildren in Sarasota, Florida, addressed the nation that evening. Within weeks, the United States led an invasion of Afghanistan to dismantle al-Qaeda and overthrow the Taliban government that had sheltered them. Bin Laden was eventually killed by United States Navy SEALs at his compound in Abbottabad, Pakistan on May 2, 2011.