The September 11 attacks were a series of four coordinated terrorist attacks by the Islamic terrorist group called Al Qaida led by Osama Bin Laden on American soil in the morning of Tuesday September 11,2001. The attacks killed over an estimate of 3,000 people and injured over 6,000 others and caused at least $10 billion in property and damages caused from the attacks. Both United Airlines and American Airlines were hijacked by 19 Al Qaida hijackers and both planes were targeted to hit the World Trade Center. Two of the planes, American Airlines Flight 11 and United Airlines Flight 175, were crashed into the North and South towers, respectively, of the World Trade Center complex in New York City. Within an hour and 42 minutes, both 110 story towers collapsed, with falling debris and the resulting fires causing partial or complete collapse of other buildings in the World Trade Center complex, including the 47 story 7 World Trade Center tower, as well as significant damage to ten other large surrounding structures in the complex. A third plane, American Airlines Flight 77, crashed into the Pentagon (The headquarters of the United States Department of Defense) in Arlington Country, Virginia,leading to a partial collapse of the Western side of the building. The fourth plane, United Airlines Flight 93, initially was steered toward Washington D.C. but crashed crashed into a field in Stony creek Township near Pennsylvania after its passengers tried to overcome the hijackers from crashing the plane. It was the deadliest incident for firefighters and law enforcement officers in the history of the United States, with 343 and 72 killed respectively. The suspicion of the attack on the World Trade Center quickly fell on Al Qaida and the United States responded to the terrorist attack by launching the War on Terror and invading Afghanistan to depose the Taliban terrorist group, which had harbored Al Qaida. Many countries had strengthened their anti terrorism legislation and expanded the powers of law enforcement and intelligence agencies to prevent terrorist attacks. Although Al Qaida’s leader, Osama Bin Laden, initially denied any involvement, in 2004 he claimed responsibility for the 9/11 attacks. Al Qaida and bin laden cited US support of Israel, the presence of US troops in Saudi Arabia and sanctions against Iraq as motives. Having evaded capture for almost a decade, Osama Bin Laden was located and killed by SEAL Team Six of the US Navy in May 2011. The destruction of the World Trade Center and nearby infrastructure caused serious damage to the economy of Lower Manhattan and had a significant effect on global markets, closing Wall Street until September 17 and the civilian airspace in the US and Canada until September 13.