On September 11, 2001, 19 men hijacked four commercial jets, intentionally crashing two of them into each of the Twin Towers of the World Trade Center and one into the Pentagon. The fourth plane crashed in a field in Pennsylvania after passengers, aware of the earlier attacks, stormed the cockpit. All passengers on the four jets were killed, along with 125 at the Pentagon and more than 2,600 at the World Trade Center. In all, almost 3,000 people were killed in the attacks. The U.S. government quickly blamed al Qaeda, and the group has since acknowledged that it masterminded and executed the attacks.