There were a total of 2,996 deaths, including the 19 hijackers and 2,977 victims. The victims were distributed as follows: 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.
More than 90 countries lost citizens in the attacks on the World Trade Center. In 2007, the New York City medical examiner's office added Felicia Dunn-Jones to the official death toll from the al-Quaeda terrorist attacks of September 11, 2001. Dunn-Jones died in February of 2002 from a lung condition which was linked to exposure to dust during the collapse of the World Trade Center. Leon Heyward, who died of lymphoma in 2008, was added to the official death toll in 2009.
At the time of the incident, media reports suggested that tens of thousands might have been killed in the attacks, as on any given day upwards of 100,000 people could be inside the towers. Estimates of the number of people in the Twin Towers when attacked on September 11, 2001 range between 14,000 and 19,000. NIST estimated that approximately 17,400 civilians were in the World Trade Center complex at the time of the September 11, 2001 attacks. Turnstile counts from the Port Authority indicate that the number of people typically in the Twin Towers by 8:45 a.m. was 14,154.
Only 14 people escaped from the impact zone of the South Tower after it was hit and only four people from the floors above it. Individuals escaped from as high up on the South Tower as the 91st floor after initial impact. They escaped via Stairwell A, the only stairwell which had been left intact after the impact. It is speculated that Stairwell A in the South Tower was not only intact after the impact of United Airlines Flight 175, but that it was also passable until the South Tower collapsed at 9:59 AM that day. Since communication between 911 operators, FDNY and NYPD responders was disorganized, most individuals who were trapped were unaware of the passable status of Stairwell A and were instead told to wait for assistance by rescue personnel. No one was able to escape from above the impact zone in the North Tower after it was hit, as all stairwells and elevator shafts on those floors were destroyed. After the collapse of the towers, only 23 survivors who were in or below the towers escaped from the debris, including 15 rescue workers. The last survivor to be removed alive from the WTC collapse debris was Genelle Guzman-McMillian, who was removed at 12:30 PM on September 12th, 27 hours after its initial collapse. She was a Port Authority employee who worked on the 64th floor of the North Tower.  A total of 6,294 people were reported to have been treated in area hospitals for injuries related to the 9/11 attacks in New York City.
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