2001September 1 1 am [2]? (EST), two passenger airliners hijacked by terrorists crashed into the World Trade Center 1 building in New York and the World Trade Center Building 2 respectively. After the attack, two buildings collapsed one after another, and five other buildings of the World Trade Center collapsed and were damaged in the earthquake. At about 9 o'clock, another hijacked passenger plane crashed into the Pentagon of the US Department of Defense in Washington, USA, and the local structure of the Pentagon was damaged and collapsed.

After the incident, troops all over the United States entered the highest alert state. Although the Taliban issued a statement saying that the terrorist incident had nothing to do with bin Laden, the US government still identified bin Laden as the prime suspect in this terrorist attack. In response to this attack, the United States launched the "war on terror", invaded Afghanistan, destroyed the Taliban hiding Al Qaeda terrorists, and passed the USA Patriot Act. 10 On 7 October, US President george walker bush announced that he would launch a military strike against Afghanistan.

The "9 1 1" incident was the most serious terrorist attack in the United States, with a total of 2,996 victims. There are different statistics about the property losses in this incident. According to a report released by the United Nations, the economic losses caused by this terrorist attack amounted to 200 billion US dollars, equivalent to 2% of the GDP of that year. The loss caused by this incident to the global economy even reached about 1 trillion dollars.