Casualties of the September 11 attacks

A photo montage of the September 11 attacks. Clockwise from top left: World Trade Center burning; Flight 175 crashes into the south tower; recovery of one of the engines from Flight 93; Pentagon crash video; fireman calls for 10 more rescue workers; Western Ring of the Pentagon.

During the September 11 attacks of 2001, 2,977 people were killed (excluding the 19 hijackers) and more than 6,000 others injured.[1][2] The immediate deaths included 265 on the four planes (including the terrorists), 2,606 in the World Trade Center and in the surrounding area, and 125 at the Pentagon.[3][4] The attacks were the deadliest terrorist act in world history, and the most devastating foreign attack on United States soil since the attack on Pearl Harbor on December 7, 1941.[5]

Most of those who perished were civilians except for 343 firefighters and 71 law enforcement officers who died in the World Trade Center and on the ground in New York City,[6] and another law enforcement officer who died when United Airlines Flight 93 crashed into a field near Shanksville, Pennsylvania,[7] 55 military personnel who died at the Pentagon in Arlington County, Virginia,[8] and the 19 terrorists who died on board the four aircraft. Overall, 2,605 U.S. citizens, including 2,135 civilians, died in the attacks, while an additional 372 non-U.S. citizens (excluding the 19 perpetrators) also perished, which represented about 12% of the total.[3] More than 90 countries lost citizens in the attacks,[9] including the United Kingdom (67 deaths), the Dominican Republic (47 deaths), and India (41 deaths).

2,974 victims were confirmed to have died in the initial attacks.[10] In 2007, the New York City medical examiner's office began to add people who died of illnesses caused by exposure to dust from the site to the official death toll. The first such victim was a woman, a civil rights lawyer, who had died from a chronic lung condition in February 2002.[11] In September 2009, the office added a man who died in October 2008,[12] and in 2011, a male accountant who had died in December 2010.[13] This raises the number of victims at the World Trade Center site to 2,753, and the overall 9/11 death toll to 2,996.[2]

As of August 2013, medical authorities concluded that 1,140 people who worked, lived, or studied in Lower Manhattan at the time of the attack have been diagnosed with cancer as a result of "exposure to toxins at Ground Zero".[14] It has been reported that over 1,400 9/11 rescue workers who responded to the scene in the days and months after the attacks have since died.[15] At least 11 pregnancies were lost as a result of 9/11.[16]

Most tall buildings in the United States at the time were not designed for complete evacuation during a crisis, even after the 1993 World Trade Center bombing. It was also procedural for announcements in the case of high-rise fire safety for individuals to stay in their offices unless they were near the burning floor.[17] The two World Trade Center buildings housed three stairwells in the center core of each tower, with the stairwells being 70 feet apart in the North Tower and about 200 feet apart in the South Tower. The three stairwells were labeled A, B, and C, and were as tall as the buildings with two built to 44 inches in width and the third being 56 inches wide.[18]

At the time of the attacks, media reports suggested that tens of thousands might have been killed, 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 Tuesday, September 11, 2001, range between 14,000 and 19,000. The National Institute of Standards and Technology estimated that approximately 17,400 civilians were in the World Trade Center complex at the time of the attacks.[19] Turnstile counts from the Port Authority indicate that the number of people typically in the Twin Towers by 10:30 am was 14,154.[20]

In interviews with 271 survivors, researchers in 2008 found that only about 8.6% had fled as soon as the alarm was raised while about 91.4% stayed behind to wait for more information or carrying out at least one additional task (collecting belongings/calling a family member). The interviews also showed that 82% of those who were evacuating stopped at least once during their way down, due to congestion on the stairs, to take a rest, or due to environmental conditions (smoke/debris/fire/water).[21]

In the moments after Flight 11 struck the North Tower, the roughly 8,000 people on the floors below the point of impact (the 93rd to 99th floors) were faced with a harrowing scenario. The towers of the World Trade Center complex had not been designed to facilitate a mass evacuation of everybody in the buildings, and in each tower there were only three narrow stairwells descending to the ground level. Another hindrance to the evacuation of the World Trade Center was that as the planes struck, the force of the impact caused the buildings to shift enough to jam doors in their frames, and stairwells became blocked by broken wall boards,[22] trapping dozens of people throughout the building, mostly on the floors closer to the impact zone. For those that were above the point of impact, many were trapped within their offices, with one victim relaying to 911 after the first plane hit that the stairs were inaccessible for the 106th floor.[23] At least 28 people were freed on the 86th and 89th floors by members of the Port Authority office workers who had to pry open jammed doors.[22]

Many people began to evacuate via the stairs on their own, while others chose to wait for instructions from the Port Authority of New York and New Jersey. Others who chose to evacuate were also pushed into action by loved ones who had been able to contact them.[23] As evacuees descended down the staircases in the North Tower, they were directed to descend to the concourse level beneath the World Trade Center complex, where the mall was located. Others who managed to escape credit the "Survivors Staircase," an outdoor staircase that survived the disaster, and World Trade Center workers who knew escape routes. A survivor stated "Between the 11th floor and the 9th floor, we wound through this maze. When we got to the plaza level we were walking through and there was one emergency light on. There was water up to our calves. All of a sudden there was a voice. We saw someone in a miner hat. He opened the door and said 'Just keep going.'"[24]

When first responders arrived at the Ground Zero, and they were alerted to the fire above the 78th floor, teams were ordered to help evacuate occupants of the tower.[25] Within moments of Flight 11's impact, the Port Authority issued a complete evacuation of the North Tower.

Meanwhile, in the South Tower, many people saw what had happened in the North Tower and chose to evacuate as a precaution. However, the major hindrance to this process was that for the 17 minutes between the impacts of Flight 11 and Flight 175, it had not yet been determined that a terrorist attack was unfolding, and as a result the Port Authority in the South Tower spread the word via the building's intercom system and security guards for workers in the South Tower to remain in their offices.[26] In a phone message to his wife by a victim who worked for AON Risk Management, part of the initial announcement can be heard stating: "May I have your attention, please. Repeating this message: the situation occurred in Building 1. If conditions warrant on your floor, you may wish to start an orderly evacuation."[17] A package deliverer told reporters he heard the first crash and as he evacuated he heard "The building is secure. The safest place is inside; stay calm and do not leave." Others who ignored the message were met with officials at the lobby who told them to return to their respective floors.[27] In a recorded radio conversation about two minutes after the first plane hit, the director of the South Tower stated "I'm not going to do anything until we get orders from the Fire Department or somebody."[17] This was done in order to avoid overcrowding on the plaza and concourse levels, which was feared would slow the evacuation and rescue operations in the North Tower.[28]

Despite the announcements, thousands of people continued to evacuate the South Tower. In the South Tower between the 78th Floor Sky Lobby and the Observation Deck on the 107th and 110th Floors, there were an estimated 2,000 employees, including 1,100 on the floors occupied by AON Insurance (the 92nd and the 98th through 105th). One of AON's executives, Eric Eisenberg, initiated the evacuation of their floors within moments of the impact of Flight 11.[29] A similar evacuation was carried out on the floors occupied by Fiduciary Trust, on the 90th, 94th–97th floors, as well as in the offices of Fuji Bank (on floors 79–82), CSC (floor 87)[30] and Euro Brokers on floor 84, which occupied the floors directly above the 78th Floor Sky Lobby. Executives such as Eisenberg instructed their employees to take the stairs down to the 78th floor Sky Lobby, where they could take an express elevator to the ground level and exit the building.

Many were aided in their evacuation by other building occupants such as Welles Remy Crowther, who was extremely identifiable due to the red bandana around his mouth, and who helped guide groups of evacuees to safety.[31] Within a window of roughly 17 minutes, between 8:46 AM and 9:03 AM, an estimated 1,400 people successfully evacuated the upper floors of the South Tower, while roughly 600 people did not. At the moment of the impact of Flight 175, an estimated 200 people had packed into the Sky Lobby on the 78th Floor and were waiting for the express elevators. Almost all of these people then died, as the lobby was in the lower section of Flight 175's impact zone.[31][32][33]

World Trade Center 3 is also known as the World Trade Center Hotel, the Vista Hotel, and the Marriott Hotel. During evacuations of the two larger towers, the twenty-two story hotel was used as an evacuation runway for about 1,000 people who were evacuating from the area.[34] A majority of the registered 940 guests at the hotel began to evacuate after alarms were raised due to a piece of one of the plane's landing gear landing on the top floor of the pool.[34] Some did not immediately do so, with at least one guest recounting that he woke up to the first plane hitting the North Tower, and went back to bed only to be awoken by the impact of the plane hitting the South Tower. He then watched the news and took a shower, got dressed, and gathered his belongings before evacuating after watching the South Tower collapse.[35] The guests and others who were evacuated through the hotel were guided by hotel staff through the hotel's bar and outside onto Liberty Street.[36]

Once both towers had been struck, the order to evacuate the North Tower quickly spread to encompass not only the entire World Trade Center complex, but most high rise buildings in Lower Manhattan and surrounding areas as well. The evacuation of employees from the North and South towers continued past the plaza and through the concourse. Evacuees from the North Tower were directed across the full length of the concourse to 5 World Trade Center, from where they exited the complex onto Church Street. Evacuees from the South Tower were provided with a separate route in order to deter congestion, with theirs leading them to 4 World Trade Center and exiting onto Liberty Street.[citation needed]

To relieve congestion within the city and clear the evacuees and civilians, boats and ferries were used to further evacuate Lower Manhattan.[37] Some of the boats were a part of the Coast Guard, others were civilian, company or state owned, that acted independently or after seeking the permission of the Coast Guard, who initially instructed vessels to stand by and then issued a request for all available boats to participate.[38]

No one survived in or above the impact area in the North Tower.[39] There is a report of at least one survivor who had reached the 22nd floor when the tower began to collapse, and reportedly fell 15 floors and later rescued, although some find the account unreliable.[40][41]

Only 14 people escaped from the impact zone of the South Tower (floors 77 to 85) after it was struck by United Airlines Flight 175, and only four people escaped from the floors above it. Individuals escaped from the South Tower as high up as the 84th floor using stairwell A in the northwest corner, the only stairwell left intact after the impact.[28] Investigators believe that stairwell A remained passable until the South Tower collapsed at 9:59 am. Because of communication difficulties between 911 operators and FDNY and NYPD responders, most of them were unaware that stairwell A was passable and instructed survivors above the impact zone to wait for assistance by rescue personnel.[39]

After the towers collapsed, only 23 individuals in or below the towers escaped from the debris, including 15 rescue workers. The last survivor removed from the WTC collapse debris was found in the ruins of the North Tower 27 hours after its collapse.[42] An unknown number of other people survived the initial collapse, but were buried in air pockets deep beneath the rubble and could not be rescued in time.[43][44] Some were able to rescue themselves and others from the rubble by climbing through the rubble[45] or digging and listening for sounds of life in order to safely remove the victims from the rubble.[46]

As of September 28, 2008, a total of over 33,000 police officers, firefighters, responders, and community members have been treated for injuries and sickness related to the 9/11 attacks in New York City, including respiratory conditions, mental health problems like PTSD and depression, gastrointestinal conditions, and at least 4,166 cases of cancer; according to one advocacy group "more cops have died of illness linked to the attack than had perished in it".[47][48] Talk show host Jon Stewart and others succeeded in pushing for a law passed by Congress in 2015 that permanently extends health care benefits for the responders and adds five years to the victims' compensation program.[48]

September 11th Memorial fountain at base of where one of the towers once stood, and the associated museum at left

An estimated 2,606 people who were in the World Trade Center and on the ground perished in the attacks on and the subsequent collapse of the towers.[3][49] This figure consisted of 2,192 civilians (including eight EMTs and paramedics from private hospital units); 343 members of the New York City Fire Department (FDNY); and 71 law enforcement officers including 23 members of the New York City Police Department (NYPD), 37 members of the Port Authority Police Department (PAPD), five members of the New York State Office of Tax Enforcement (OTE), three officers of the New York State Office of Court Administration (OCA), one fire marshal of the New York City Fire Department (FDNY) who had sworn law enforcement powers (and was also among the 343 FDNY members killed), one member of the Federal Bureau of Investigation (FBI), one member of the New York Fire Patrol (FPNY), and one member of the United States Secret Service (USSS).[50][51] This included a bomb-sniffing dog named Sirius,[52] who was not included in the official death toll.

The average age of the dead in New York City was 40.[53] In the buildings, the youngest victim was 18 and the oldest was 79.[54][55]

1,402 people died at or above the floors of impact in the North Tower. According to the Commission Report, hundreds were killed instantly by the impact while the remainder of the fatalities were trapped above the impact zone and died after the tower collapsed. Although a few people would subsequently be found alive in the rubble following the collapse of the towers, none of these individuals were from above the impact zone.[56] John P. O'Neill was a former assistant director of the FBI who assisted in the capture of 1993 World Trade Center bomber Ramzi Yousef and was the head of security at the World Trade Center when he was killed trying to rescue people from the North Tower.[57] An additional 24 people officially remain listed as missing.[58] Cantor Fitzgerald L.P., an investment bank on the 101st–105th floors of One World Trade Center, lost 658 employees, considerably more than any other employer. Marsh Inc., located immediately below Cantor Fitzgerald on floors 93–100 (the location of Flight 11's impact), lost 295 employees and 63 consultants.[59][60] Risk Waters, a business organization, was holding a conference in Windows on the World at the time, with 81 people in attendance.[61][62]

614 people were killed at or above the floors of impact in the South Tower. Only 18 people are known to have managed to escape using staircase A before the South Tower collapsed; a further 11 people killed in the attacks are known to have been killed below the impact zone after United Airlines Flight 175 struck the South Tower. The 9/11 Commission notes that this fact strongly indicates that evacuation below the impact zones was a success, allowing most to safely evacuate before the collapse of the World Trade Center.[63]

There is no precise number of deaths that occurred within the hotel as many who sheltered in the hotel during and after the collapse of the South Tower were protected by the reinforced beams that had been installed by the Port Authority after the 1993 bombing.[64] At least two hotel employees are believed to have died during the collapse as they were outside of the safe zone.[36]

A USA Today report estimated that approximately 200 people perished inside the elevators, while only 21 escaped the elevators. Many elevators did not plunge, but were destroyed by the crash and subsequent fires, or were stranded in the shafts. A locking mechanism prevented escapees and rescuers, except on one elevator, from opening the doors on stranded elevators.[65] One survivor recounted having to pry open a narrow gap between the doors of the elevator to escape by utilizing the stairs.[66]

Before the Twin Towers collapsed, an estimated 200 people fell to their deaths from the burning towers, landing on the streets and rooftops of adjacent buildings hundreds of feet below at a speed of almost 150 miles per hour—sufficient to cause instantaneous death upon impact, but insufficient to cause unconsciousness throughout the actual fall. Most of those who fell from the World Trade Center had jumped from the North Tower.[67] To witnesses upon the ground, many of the people falling from the towers seemed to have deliberately jumped to their deaths,[68] including the person whose photograph became known as the Falling Man. The NIST report officially describes the deaths of 104 jumpers but states that this figure likely understates the true number of those who died in this manner. The sight and sound of these individuals falling from the towers, then "smashing like eggs on the ground" horrified and traumatized many witnesses. The jumpers' death certificates state the cause of death as "blunt trauma" due to homicide.[69] Some of the occupants of each tower above its point of impact made their way upward toward the roof in hope of helicopter rescue, only to find the roof access doors locked. Port Authority officers attempted to unlock the doors but control systems would not let them; in any case, thick smoke and intense heat would have prevented rescue helicopters from landing.[70]

Contrary to some conspiracy theories about Jews being warned not to go to work that day, the number of Jews who died in the attacks is variously estimated at between 270 and 400, based on the last names of the dead.[71][73][74]

The following list details the number of deaths reported by companies in business premises at the World Trade Center. The list includes WTC tenants (all buildings), vendors, visitors, independent emergency responders, and some hijacked passenger-related firms.[75]

The Pentagon Memorial honoring the victims of the 9/11 terrorist attack on the Pentagon.

125 people working at the Pentagon were killed, most of whom worked for the United States Army or the United States Navy.[76] Of those 125 deaths, 70 were civilians – 47 Army employees, six Army contractors, six Navy employees, three Navy contractors, seven Defense Intelligence Agency employees, and one Office of the Secretary of Defense contractor[77] – and 55 were members of the United States Armed Forces – 33 Navy sailors and 22 Army soldiers.[78] Lieutenant General Timothy Maude, an Army Deputy Chief of Staff, was the highest-ranking military official killed at the Pentagon.[79]

The terrorist attack at the Pentagon on 9/11 was the first deadliest foreign attack on Washington, D.C. since the burning of the U.S. capital by the British during the War of 1812.

265 fatalities aboard the 4 planes include[80] 87 civilians (including 11 crew members) and the five hijackers aboard American Airlines Flight 11; 60 civilians (including 9 crew members) and the five hijackers aboard United Airlines Flight 175;[81] 59 passengers (including 6 crew members) and the five hijackers aboard American Airlines Flight 77; and 39 civilians (including 7 crew members), a U.S. Fish and Wildlife Service officer,[82] and the four hijackers aboard United Airlines Flight 93.[83][84] The dead included eight children: five on American Airlines Flight 77, aged 3 to 11,[85] and three on United Airlines Flight 175, aged 2, 3, and 4.[86] The youngest victim was a two-and-a-half-year-old child on Flight 175 and the oldest was an 85-year-old passenger on Flight 11.[87]

Among those killed were television producer David Angell, who co-created the sitcom Frasier,[88] and actress Berry Berenson,[89] both passengers on Flight 11. Barbara Olson, television political commentator and the wife of then-U.S. Solicitor General Theodore Olson, was aboard Flight 77.[90]

Russian President Vladimir Putin signs a condolence wall to the foreign fatalities in 9/11.

Excluding the 19 perpetrators, people from 77 different countries[91] died, representing more than 12% of the total number of deaths in the attacks, almost half of whom were British, Dominican, Indian, or South Korean. The British Overseas Territory of Bermuda had the highest number of deaths per capita in the World Trade Center attack. Without accounting for some cases of dual citizenship, here is a list of their nationalities:

During the attacks and afterwards there was a large amount of toxic dust, debris and ash that was centralized around Ground Zero and created long term health problems. Toxic materials such as asbestos, lead, and mercury were in the air and the debris and many victims and first responders did not wear respirators.[134]

It was reported in 2018 that at least 15 FBI agents had died from cancer due to their roles in the aftermath and investigation of the attack.[135] Further, a medical director of the World Trade Center Health Program at Mount Sinai Hospital reported in 2018 that out of the approximately 10,000 first responders and others who were at Ground Zero and have developed cancer as a result, more than 2,000 have died due to 9/11 related illnesses.[136] The Uniformed Firefighters Association of Greater New York also reported over 170 deaths of firefighters due to 9/11-related illnesses, and that roughly 1 in 8 firefighters who were at Ground Zero have developed cancer.[137]

Identifications through DNA can be made by comparing the DNA profile of reference samples with those found in the human remains, through obtaining samples from personal items (toothbrush/hairbrush), banked biological samples, relatives, or other identified remains.[138] The extreme heat, pressures and contamination from the collapse of the buildings has caused some of the DNA to become degraded and unusable.[139] Samples were also degraded because some body fragments remained in the rubble for 8 to 10 months.[140] In response to this, the medical examiner's office and other scientific groups created new techniques to process the bone fragments. The Associated Press reported that the medical examiner's office possesses "about 10,000 unidentified bone and tissue fragments that cannot be matched to the list of the dead".[141] Bone fragments were still being found in 2006 as workers prepared the damaged Deutsche Bank Building for demolition.[142]

In order to extract the DNA, medical examiners pulverize the fragments, and compare the extracted DNA to the collection of genetic material from victims and/or their relatives, with scientists revisiting bone fragments multiple times in an attempt to identify the victims.[143] Other issues with identification is seen with those who either fell, or jumped from the top floors of the towers, as many are unsure about the identity of those who did die in this manner, or how many died in this manner.[citation needed]

As of September 11, 2012, a total of 2,753 death certificates had been filed relating to the attacks.[144] Of these, 1,588 (58%) were forensically identified from recovered physical remains.[145][146]

On April 17, 2013, five possible remains were recovered after being sifted at Fresh Kills Landfill on Staten Island. The medical examiner said evidence of a possible victim of the attacks was recovered as well two days later.[147] On June 21, 2013, the medical examiner's office matched its 1,637th victim, a 43-year-old woman, to its list of victims as a result of DNA testing of debris collected from the site. By family request, her name was not released.[148] On July 5, 2013, the medical examiner's office identified the remains of FDNY firefighter Lt. Jeffrey P. Walz, 37, after they were retested. His remains were recovered months after the attack and is now the 1,638th victim forensically identified.[149]

On August 7, 2017, the medical examiner's office matched its 1,641st victim. The victim was identified through retesting of DNA from remains recovered in 2001.[150] In 2017 it was reported that only 1,641 victims, or just under 60%, have identified remains.[143]

On July 25, 2018, the medical examiner's office matched its 1,642nd victim. The victim, 26-year-old Scott Michael Johnson, was identified through the retesting of DNA from remains recovered in 2001.[151]