On September 11, 2001, terrorists killed nearly 3,000 people and injured more than 6,000 others in the worst attack against the homeland in our nation's history.

The official death toll for the September 11, 2001, terrorist attacks is 2,977 victims, plus the 19 hijackers, bringing the total to 2,996 people. This count includes those killed at the World Trade Center in New York (2,606), the Pentagon in Virginia (125), and aboard United Airlines Flight 93 in Pennsylvania (40). The victims represented over 100 different nationalities. However, in 2026, the "total" impact of 9/11 is often discussed in broader terms because of the 9/11-related illnesses. Since the attacks, thousands of first responders and survivors have died from cancers and respiratory diseases caused by exposure to toxic dust at Ground Zero. In fact, the number of people who have died from these post-attack illnesses has now surpassed the number of people killed on the day of the attacks. As of 2026, the World Trade Center Health Program continues to monitor over 120,000 individuals. While the "official" historical death toll remains 2,977, the true human cost of the tragedy continues to rise annually as more individuals succumb to the long-term health consequences of the environmental disaster at the site.