2001. 9/11 terrorist attacks
The September 11 terrorist attacks on the US are a series of four coordinated attacks by the Islamic terrorist group al-Qaeda that kills 2,996 people, injures over 6,000 others and causes at least $10 billion in infrastructure and property damage.
As part of the attacks, four passenger airliners operated by United Airlines and American Airlines are hijacked by 19 al-Qaeda terrorists. American Airlines Flight 11 and United Airlines Flight 175 are crashed into the North and South towers of the World Trade Center complex in Lower Manhattan. Within an hour and 42 minutes, both 110-story towers collapse. A third plane, American Airlines Flight 77, is crashed into the Pentagon in Virginia and the fourth plane, United Airlines Flight 93, is flown toward Washington, DC, but crashes in Pennsylvania, after its passengers overpower the hijackers.
9/11 is the single deadliest (coordinated) terrorist attack in human history. The United States responds by launching the War on Terror and invades Afghanistan to depose the Taliban, which had failed to comply with the US demands to extradite Osama bin Laden and expel its leader, al-Qaeda, from the country. Al-Qaeda and Osama bin Laden cite US support of Israel, the presence of US troops in Saudi Arabia and sanctions against Iraq as motives for the attacks. Bin Laden is eventually located in Pakistan and killed by a Navy SEAL team in 2011 and, as a consequence of the attacks, the US has remained in a state of national emergency since 2001.