The September 11 attacks were a series of four coordinated suicide attacks by al-Qaeda on the United States on Tuesday, September 11, 2001. On that morning, 19 al-Qaeda terrorists hijacked four passenger jets. The hijackers intentionally crashed two planes into the Twin Towers of the World Trade Center in New York City, killing everyone on board and thousands of those working in the buildings. Both towers collapsed within two hours, destroying nearby buildings and damaging others. A third plane was crashed into the Pentagon in Arlington, Virginia. Hijackers had redirected the fourth plane toward Washington, D.C., targeting either the Capitol Building or the White House, but crashed it in a field near Shanksville, Pennsylvania after passengers tried to take control of the plane.Nearly 3,000 victims and all the 19 hijackers died in the attacks.Among the 2,753 victims who died in the World Trade Center were 343 firefighters and 60 police officers from New York City and the Port Authority, and 8 private emergency medical technicians and paramedics.Another 184 people were killed in the attack on the Pentagon.There were no survivors from any of the flights and the overwhelming majority of casualties were civilians, including nationals of over 70 countries.Suspicion quickly fell on al-Qaeda. Al-Qaeda leader Osama bin Laden initially denied involvement, but in 2004 he finally claimed responsibility for the attacks. Al-Qaeda and bin Laden cited U.S. support of Israel, the presence of U.S. troops in Saudi Arabia, and sanctions against Iraq as motives for the attacks. The United States responded to the attacks by launching the War on Terror, invading Afghanistan to depose the Taliban, who had harbored al-Qaeda members. It was not until May 2011 that bin Laden was found and killed. Rebuilding at the World Trade Center site began in 2002.