On 11 September 2001, 19 Al-Qaeda jihadis hijacked four passenger planes in USA airspace, crashing three of them into the World Trade Center towers and the Pentagon. After their attempt to crash the fourth plane somewhere in Washington, D.C., was thwarted by passengers, it was crashed into a field in Pennsylvania. The attack killed 2,9777 people, injured more than 25,000 others, and completely destroyed the World Trade Center complex in Lower Manhattan when the towers collapsed. It was the deadliest terrorist attack in human history. The fallout included global economic decline, heightened travel security measures around the world, the ‘War on Terror’ declared by the United States, and greater powers of surveillance granted to national governments.