War in Afghanistan (2001–present)
On the morning of 11 September 2001, a total of 19 Arab men—15 of whom were from Saudi Arabia—carried out four coordinated attacks in the United States. Four commercial passenger jet airliners were hijacked. The hijackers – members of al-Qaeda's Hamburg cell – intentionally crashed two of the airliners into the Twin Towers of the World Trade Center in New York City, killing everyone on board and more than 2,000 people in the buildings. Both buildings collapsed within two hours from damage related to the crashes, destroying nearby buildings and damaging others. The hijackers crashed a third airliner into the Pentagon in Arlington, Virginia, just outside Washington, D.C. The fourth plane crashed into a field near Shanksville, in rural Pennsylvania, after some of its passengers and flight crew attempted to retake control of the plane, which the hijackers had redirected toward Washington, D.C., to target the White House, or the U.S. Capitol. No one aboard the flights survived. According to the New York State Health Department, the death toll among responders including firefighters and police was 836 as of June 2009. Total deaths were 2,996, including the 19 hijackers.
Siraj Wahhaj
Wahhaj was one of 170 people identified by US Attorney Mary Jo White in 1995 as "unindicted persons who may be alleged as co-conspirators" in the 1993 World Trade Center bombing, but was never charged, and denies any involvement with the bombing. 
Wahhaj was a defence witness at the trial of the Blind Sheikh, Omar Abdel-Rahman, the former leader of the Egyptian terrorist organization, Gama'a al-Islamiyya.