September 11 attacks, also called 9/11 attacks, series of airline hijackings and suicide attacks committed in 2001 by 19 militants associated with the Islamic extremist group al-Qaeda against targets in the United States, the deadliest terrorist attacks on American soil in U.S. history. Today 9/11 is now a day to remember and reflect on what happen back then and to remember who we lost and how we built back up from the attack.