On September 11, 2001, 19 al-Qaeda terrorists took control of four commercial aircraft and used them as suicide weapons in a series of four coordinated acts of terrorism to strike the World Trade Center in New York City, The Pentagon in Arlington County, Virginia, and an additional target in Washington, D.C. Two aircraft hit the World Trade Center while the third hit the Pentagon. A fourth plane did not arrive at its target, but crashed into a field in Pennsylvania after a passenger revolt. The intended target is believed to have been the United States Capitol. As a result, 2,977 victims were killed, making it the deadliest foreign attack on U.S. soil, exceeding Japan's surprise attack on Pearl Harbor in Honolulu, Hawaii, on December 7, 1941, which killed 2,335 members of the United States Armed Forces and 68 civilians. The effort was carefully planned by al-Qaeda, which sent 19 terrorists to take over Boeing 757 and Boeing 767 aircraft, operated by American Airlines and United Airlines. Background Al-Qaeda's origins date to 1979 when the Soviet Union invaded Afghanistan. Soon after the invasion, Osama bin Laden traveled to Afghanistan and helped organize Arab mujahideen. Together with Abdullah Azzam, a Palestinian-Jordanian who influenced bin Laden, they formed Maktab al-Khidamat (MAK) in 1984, to provide support for Arab mujahideen who came to join the jihad in Afghanistan. Toward the end of the 1980s, the Soviets were retreating in defeat. Bin Laden and Azzam discussed the future of MAK and what to do with the mujahideen force that had built up. Bin Laden and Azzam both wanted to use the force as a "rapid reaction force" to defend oppressed Muslims around the world. Bin Laden wanted to train the mujahideen in terrorist tactics, but Azzam strongly disagreed with this approach, issuing a fatwa saying that it would violate Islamic law. Azzam reiterated the hadith that orders Muslims to kill no women or children. In November 1989, soon after bin Laden and Azzam split, Azzam was killed in Peshawar, Pakistan. Azzam and his two sons were travelling to Jummah (Friday prayer) when a remote-control-activated bomb detonated, killing them. It is unknown for certain if bin Laden was behind this, but is thought unlikely. Nonetheless, bin Laden was then free to take full control of MAK, laying the groundwork for al-Qaeda. Under the guidance of Dr. Ayman al-Zawahiri, bin Laden became more radical. In 1991, bin