The attacks killed 2,996 people, injured over 6,000 others, and caused at least $10 billion in infrastructure and property damage. Additionally, masses died of 9/11-related cancer and respiratory diseases in the months and years following the attacks.
On 11 September 2001, passenger airliners operated by two major U.S. passenger air carriers (United Airlines and American Airlines) were hijacked by 19 al-Qaeda terrorists. The planes were 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 collapsed. Debris and the resulting fires caused a partial or complete collapse of all 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.
A third plane – American Airlines – was crashed into the headquarters of the United States Department of Defense in Arlington County, Virginia, which led to a partial collapse of the building’s west side.
