The 9/11 attacks were a series of four coordinated terrorist attacks by the Islamic terrorist group al Qaeda against the United States on the morning of Tuesday, September 11, 2001. The attacks killed 2,977 people (not counting the 19 hijackers who also died), injured over 6,000 others, and caused at least $10 billion in infrastructure and property damage.

Additional people have died of 9/11 related cancer and respiratory diseases in the months and years following the attacks.