We will never forget

There were a total of 2,996 deaths, including the 19 hijackers and 2,977 victims. The victims included 246 on the four planes (from which there were no survivors), 2,606 in New York City in the towers and on the ground, and 125 at the Pentagon. All the deaths in the attacks were civilians, except for 55 military personnel killed at the Pentagon.

Over 90% of the workers and visitors who died in the towers had been at or above the points of impact. In the North Tower 1,355 people at or above the point of impact were trapped and died of smoke inhalation, fell or jumped from the tower to escape the smoke and flames, or were killed in the building's eventual collapse. A further 107 people below the point of impact did not survive. In the South Tower, one stairwell remained intact allowing 18 people to escape from above the point of impact. 630 people died in the South Tower which was fewer than half of the number killed in the North Tower.  Casualties in the South Tower were significantly reduced by the decision of some occupants to start evacuating when the North Tower was struck.

At least 200 people fell or jumped to their deaths from the burning towers, landing on the streets and rooftops of adjacent buildings hundreds of feet below. Some occupants of each tower above the point of impact made their way upward toward the roof in hope of helicopter rescue, but the roof access doors were locked. No plan existed for helicopter rescues, and the thick smoke and intense heat would have prevented helicopters from approaching.
A total of 411 emergency workers who responded to the scene died as they tried to rescue people and fight fires. The New York City Fire Department (FDNY) lost 341 firefighters and 2 paramedics. The New York City Police Department (NYPD) lost 23 officers. The Port Authority Police Department lost 37 officers.  Eight emergency medical technicians (EMTs) and paramedics from private emergency medical services units were killed.