American Airlines Flight 77 was a scheduled American Airlines domestic transcontinental passenger flight from Washington Dulles International Airport in Dulles, Virginia, to Los Angeles International Airport in Los Angeles, California. The Boeing 757-223 aircraft serving the flight was hijacked by five men affiliated with al-Qaeda on September 11, 2001, as part of the September 11 attacks. They deliberately crashed the plane into the Pentagon in Arlington County, Virginia, near Washington, D.C., killing all 64 people on board, including the five hijackers and six crew, as well as 125 people in the building.
Less than 35 minutes into the flight, the hijackers stormed the cockpit. They forced the passengers, crew, and pilots to the rear of the aircraft. Hani Hanjour, one of the hijackers who was trained as a pilot, assumed control of the flight. Unknown to the hijackers, passengers aboard made telephone calls to friends and family and relayed information on the hijacking.
The hijackers crashed the aircraft into the western side of the Pentagon at 09:37 EDT. Many people witnessed the crash, and news sources began reporting on the incident within minutes. The impact severely damaged an area of the Pentagon and caused a large fire. A portion of the building collapsed; firefighters spent days working to fully extinguish the blaze. The damaged sections of the Pentagon were rebuilt in 2002, with occupants moving back into the completed areas that August. The 184 victims of the attack are memorialized in the Pentagon Memorial adjacent to the crash site. The 1.93-acre (7,800 m 2) park contains a bench for each of the victims, arranged according to their year of birth and ranging from 1930 to 1998.
Hanjour trained at the CRM Airline Training Center in Scottsdale, Arizona, earning his FAA commercial pilot's certificate in April 1999. He had wanted to be a commercial pilot for the Saudi national airline but was rejected when he applied to the civil aviation school in Jeddah in 1999. Hanjour's brother later explained that, frustrated at not finding a job, Hanjour "increasingly turned his attention toward religious texts and cassette tapes of militant Islamic preachers".  Hanjour returned to Saudi Arabia after being certified as a pilot, but left again in late 1999, telling his family that he was going to the United Arab Emirates to work for an airline.  Hanjour likely went to Afghanistan, where Al-Qaeda recruits were screened for special skills they might have. Already having selected the Hamburg cell members, Al Qaeda leaders selected Hanjour to lead the fourth team of hijackers.
Alec Station, the CIA's unit dedicated to tracking Osama bin Laden, had discovered that two of the other hijackers, al-Hazmi and al-Mihdhar, had multiple-entry visas to the United States well before 9/11. Two FBI agents inside the unit tried to alert FBI headquarters, but CIA officers rebuffed them.
In December 2000, Hanjour arrived in San Diego, joining "muscle" hijackers Nawaf al-Hazmi and Khalid al-Mihdhar, who had been there since January 2000.  Soon after arriving, Hanjour and Hazmi left for Mesa, Arizona, where Hanjour began refresher training at Arizona Aviation. 
In April 2001, they relocated to Falls Church, Virginia, where they awaited the arrival of the remaining "muscle" hijackers.  One of these men, Majed Moqed, arrived on May 2, 2001, with Flight 175 hijacker Ahmed al-Ghamdi from Dubai at Dulles International Airport. They moved into an apartment with Hazmi and Hanjour. 
On May 21, 2001, Hanjour rented a room in Paterson, New Jersey, where he stayed with other hijackers through the end of August. The last Flight 77 "muscle" hijacker, Salem al-Hazmi, arrived on June 29, 2001, with Abdulaziz al-Omari (a hijacker of Flight 11) at John F. Kennedy International Airport from the United Arab Emirates. They stayed with Hanjour. 
Hanjour received ground instruction and did practice flights at Air Fleet Training Systems in Teterboro, New Jersey, and at Caldwell Flight Academy in Fairfield, New Jersey.  Hanjour moved out of the room in Paterson and arrived at the Valencia Motel in Laurel, Maryland, on September 2, 2001. While in Maryland, Hanjour and fellow hijackers trained at Gold's Gym in Greenbelt. On September 10, he completed a certification flight, using a terrain recognition system for navigation, at Congressional Air Charters in Gaithersburg, Maryland.  
According to a U.S. State Department cable leaked in the WikiLeaks dump in February 2010, the FBI has investigated another suspect, Mohammed al-Mansoori. He had associated with three Qatari citizens who flew from Los Angeles to London (via Washington) and Qatar on the eve of the attacks, after allegedly surveying the World Trade Center and the White House. U.S. law enforcement officials said that the data about the four men was "just one of many leads that were thoroughly investigated at the time and never led to terrorism charges".  An official added that the three Qatari citizens have never been questioned by the FBI. Eleanor Hill, the former staff director for the congressional joint inquiry on the September 11 attacks, said the cable reinforces questions about the thoroughness of the FBI's investigation. She also said that the inquiry concluded that the hijackers had a support network that helped them in different ways. 
The three Qatari men were booked to fly from Los Angeles to Washington on September 10, 2001, on the same plane that was hijacked and piloted into the Pentagon on the following day. Instead, they flew from Los Angeles to Qatar, via Washington and London. While the cable said that Mansoori was currently under investigation, U.S. law enforcement officials said that there was no active investigation of him or of the Qatari citizens mentioned in the cable. 
The American Airlines Flight 77 aircraft was a Boeing 757-223 (registration N644AA).   The aircraft was built and had its first flight in 1991.  The flight crew included pilot Charles Burlingame (a Naval Academy graduate and former fighter pilot), First Officer David Charlebois, and flight attendants Michele Heidenberger, Jennifer Lewis, Kenneth Lewis, and Renee May.  The capacity of the aircraft was 188 passengers, but with 58 passengers on September 11, the load factor was 33 percent. American Airlines said that Tuesdays were the least-traveled day of the week, with the same load factor seen on Tuesdays in the previous three months for Flight 77. 
Boarding and departure
On the morning of September 11, 2001, the five hijackers arrived at Washington Dulles International Airport. At 07:15, Khalid al-Mihdhar and Majed Moqed checked in at the American Airlines ticket counter for Flight 77,  arriving at the passenger security checkpoint a few minutes later at 07:18.  Both men set off the metal detector and were put through secondary screening. Moqed continued to set off the alarm, so he was searched with a hand wand.  The Hazmi brothers checked in together at the ticket counter at 07:29. Hani Hanjour checked in separately and arrived at the passenger security checkpoint at 07:35.  Hanjour was followed minutes later at the checkpoint by Salem and Nawaf al-Hazmi, who also set off the metal detector's alarm. The screener at the checkpoint never resolved what set off the alarm. As seen in security footage later released, Nawaf Hazmi appeared to have an unidentified item in his back pocket. Utility knives up to four inches were permitted at the time by the Federal Aviation Administration (FAA) as carry-on items.   The passenger security checkpoint at Dulles International Airport was operated by Argenbright Security, under contract with United Airlines. 
The hijackers were all selected for extra screening of their checked bags. Hanjour, al-Mihdhar, and Moqed were chosen by the Computer Assisted Passenger Prescreening System criteria, while the brothers Nawaf and Salem al-Hazmi were selected because they did not provide adequate identification and were deemed suspicious by the airline check-in agent. Hanjour, Mihdhar, and Nawaf al-Hazmi did not check any bags for the flight. Checked bags belonging to Moqed and Salem al-Hazmi were held until they boarded the aircraft. 
Flight 77 was scheduled to depart for Los Angeles at 08:10; 58 passengers boarded through Gate D26, including the five hijackers. Excluding the hijackers, of the 59 other passengers and crew on board, there were 26 men, 22 women, and five children ranging in age from three to eleven. On the flight, Hani Hanjour was seated up front in 1B, while Salem and Nawaf al-Hazmi were seated in first class in seats 5E and 5F. Majed Moqed and Khalid al-Mihdhar were seated further back in 12A and 12B, in economy class.  Flight 77 left the gate on time and took off from Runway 30 at Dulles at 08:20. 
The 9/11 Commission estimated that the flight was hijacked between 08:51 and 08:54, shortly after American Airlines Flight 11 struck the World Trade Center and not too long after United Airlines Flight 175 had been hijacked. The last normal radio communications from the aircraft to air traffic control occurred at 08:50:51.  Unlike the other three flights, there were no reports of anyone being stabbed or a bomb threat and the pilots were not immediately killed but shoved to the back of the plane with the rest of the passengers. At 08:54, the plane began to deviate from its normal, assigned flight path and turned south. Two minutes later at 08:56, the plane's transponder was switched off.  The hijackers set the flight's autopilot on a course heading east towards Washington, D.C. 
The FAA was aware at this point that there was an emergency on board the airplane. By this time, Flight 11 had already crashed into the North Tower of the World Trade Center and Flight 175 was known to have been hijacked and was within minutes of striking the South Tower. After learning of this second hijacking involving an American Airlines aircraft and the hijacking involving United Airlines, American Airlines' executive vice president Gerard Arpey ordered a nationwide ground stop for the airline.  The Indianapolis Air Traffic Control Center, as well as American Airlines dispatchers, made several failed attempts to contact the aircraft. At the time the airplane was hijacked, it was flying over an area of limited radar coverage. With air controllers unable to contact the flight by radio, an Indianapolis official declared that the Boeing 757 had possibly crashed at 09:09.
Two people on the aircraft made phone calls to contacts on the ground. At 09:12, flight attendant Renee May called her mother, Nancy May, in Las Vegas.  During the call, which lasted nearly two minutes, May said her flight was being hijacked by six persons, and staff and passengers had been moved to the rear of the airplane.   May asked her mother to contact American Airlines, which she and her husband promptly did;  American Airlines was already aware of the hijacking. Between 09:16 and 09:26, passenger Barbara Olson called her husband, United States Solicitor General Theodore Olson, and reported that the airplane had been hijacked and that the assailants had box cutters and knives.  She reported that the passengers, including the pilots, had been moved to the back of the cabin and that the hijackers were unaware of her call. A minute into the conversation, the call was cut off. Theodore Olson contacted the command center at the Department of Justice, and tried unsuccessfully to contact Attorney General John Ashcroft.  About five minutes later, Barbara Olson called again, told her husband that the "pilot" (possibly Hanjour on the cabin intercom) had announced the flight was hijacked, and asked, "What do I tell the pilot to do?"  Ted Olson asked her location and she reported the plane was flying low over a residential area. He told her of the attacks on the World Trade Center. Soon afterward, the call cut off again. 
An airplane was detected again by Dulles controllers on radar screens as it approached Washington, turning and descending rapidly. Controllers initially thought this was a military fighter, due to its high speed and maneuvering.  Reagan Airport controllers asked a passing Air National Guard Lockheed C-130 Hercules to identify and follow the aircraft. The pilot, Lt. Col. Steven O'Brien, told them it was a Boeing 757 or 767, and its silver fuselage meant that it was probably an American Airlines jet. He had difficulty picking out the airplane in the "East Coast haze", but then saw a "huge" fireball, and initially assumed it had hit the ground. Approaching the Pentagon, he saw the impact site on the building's west side and reported to Reagan control, "Looks like that aircraft crashed into the Pentagon, sir." 
According to the 9/11 Commission Report, as Flight 77 was 5 miles (8.0 km) west-southwest of the Pentagon, it made a 330-degree turn. At the end of the turn, it was descending through 2,200 feet (670 m), pointed toward the Pentagon and downtown Washington. Hani Hanjour advanced the throttles to maximum power and dived toward the Pentagon. While level above the ground and seconds from the crash, the wings knocked over five street lampposts and the right wing struck a portable generator, creating a smoke trail seconds before smashing into the Pentagon. Flight 77, flying at 530 mph (853 km/h, 237 m/s, or 460 knots) over the Navy Annex Building adjacent to Arlington National Cemetery,  crashed into the western side of the Pentagon in Arlington County, Virginia, just south of Washington, D.C., at 09:37:46.  The plane hit the Pentagon at the first-floor level, and at the moment of impact, the airplane was rolled slightly to the left, with the right wing elevated.  The front part of the fuselage disintegrated on impact, while the mid and tail sections moved for another fraction of a second, with tail section debris penetrating furthest into the building. In all, the airplane took eight-tenths of a second to fully penetrate 310 feet (94 m) into the three outermost of the building's five rings and unleashed a fireball that rose 200 feet (61 m) above the building.
At the time of the attacks, approximately 18,000 people worked in the Pentagon, which was 4,000 fewer than before renovations began in 1998.  The section of the Pentagon that was struck, which had recently been renovated at a cost of $250 million,  housed the Naval Command Center. 
In all, there were 189 deaths at the Pentagon site, including the 125 in the Pentagon building in addition to the 64 on board the aircraft. Passenger Barbara Olson was en route to a recording of the TV show Politically Incorrect.  A group of children, their chaperones, and National Geographic Society staff members were also on board, embarking on an educational trip west to the Channel Islands National Marine Sanctuary near Santa Barbara, California.  The fatalities at the Pentagon included 55 military personnel and 70 civilians.  Of those 125 killed, 92 were on the first floor, 31 were on the second floor, and two were on the third. Seven Defense Intelligence Agency civilian employees were killed while the Office of the Secretary of Defense lost one contractor. The U.S. Army suffered 75 fatalities—53 civilians (47 employees and six contractors) and 22 soldiers—while the U.S. Navy suffered 42 fatalities—nine civilians (six employees and three contractors) and 33 sailors. Lieutenant General Timothy Maude, an Army Deputy Chief of Staff, was the highest-ranking military officer killed at the Pentagon; also killed was retired Rear Admiral Wilson Flagg, a passenger on the plane.  LT Mari-Rae Sopper, JAGC, USNR, was also on board the flight, and was the first Navy Judge Advocate ever to be killed in action.  Another 106 were injured on the ground and were treated at area hospitals.
On the side where the plane hit, the Pentagon is bordered by Interstate 395 and Washington Boulevard. Motorist Mary Lyman, who was on I-395, saw the airplane pass over at a "steep angle toward the ground and going fast" and then saw the cloud of smoke from the Pentagon. Omar Campo, another witness, was cutting the grass on the other side of the road when the airplane flew over his head, and later recalled:
I was cutting the grass and it came in screaming over my head. I felt the impact. The whole ground shook and the whole area was full of fire. I could never imagine I would see anything like that here. 
Afework Hagos, a computer programmer, was on his way to work and stuck in a traffic jam near the Pentagon when the airplane flew over. "There was a huge screaming noise and I got out of the car as the plane came over. Everybody was running away in different directions. It was tilting its wings up and down like it was trying to balance. It hit some lampposts on the way in."  Daryl Donley witnessed the crash and took some of the first photographs of the site. 
USA Today reporter Mike Walter was driving on Washington Boulevard when he witnessed the crash, which he recounted,
I looked out my window and I saw this plane, this jet, an American Airlines jet, coming. And I thought, 'This doesn't add up, it's really low.' And I saw it. I mean it was like a cruise missile with wings. It went right there and slammed right into the Pentagon. 
Terrance Kean, who lived in a nearby apartment building, heard the noise of loud jet engines, glanced out his window, and saw a "very, very large passenger jet". He watched "it just plow right into the side of the Pentagon. The nose penetrated into the portico. And then it sort of disappeared, and there was fire and smoke everywhere." Tim Timmerman, who is a pilot himself, noticed American Airlines markings on the aircraft as he saw it hit the Pentagon.  Other drivers on Washington Boulevard, Interstate 395, and Columbia Pike witnessed the crash, as did people in Pentagon City, Crystal City, and other nearby locations.
Former Georgetown University basketball coach John Thompson had originally booked a ticket on Flight 77. As he would tell the story many times in the following years, including a September 12, 2011 interview on Jim Rome's radio show, he had been scheduled to appear on that show on September 12, 2001. Thompson was planning to be in Las Vegas for a friend's birthday on September 13, and initially insisted on traveling to Rome's Los Angeles studio on the 11th. However, this did not work for the show, which wanted him to travel on the day of the show. After a Rome staffer personally assured Thompson that he would be able to travel from Los Angeles to Las Vegas immediately after the show, Thompson changed his travel plans. He felt the impact from the crash at his home near the Pentagon. 
Rescue and recovery
Rescue efforts began immediately after the crash. Almost all the successful rescues of survivors occurred within half an hour of the impact. Initially, rescue efforts were led by the military and civilian employees within the building. Within minutes, the first fire companies arrived and found these volunteers searching near the impact site. The firemen ordered them to leave as they were not properly equipped or trained to deal with the hazards. The Arlington County Fire Department (ACFD) assumed command of the immediate rescue operation within 10 minutes of the crash. ACFD Assistant Chief James Schwartz implemented an incident command system (ICS) to coordinate response efforts among multiple agencies. It took about an hour for the ICS structure to become fully operational. Firefighters from Fort Myer and Reagan National Airport arrived within minutes.  Rescue and firefighting efforts were impeded by rumors of additional incoming planes. Chief Schwartz ordered two evacuations during the day in response to these rumors.
As firefighters attempted to extinguish the fires, they watched the building in fear of a structural collapse. One firefighter remarked that they "pretty much knew the building was going to collapse because it started making weird sounds and creaking". Officials saw a cornice of the building move and ordered an evacuation. Minutes later, at 10:10, the upper floors of the damaged area of the Pentagon collapsed. The collapsed area was about 95 feet (29 m) at its widest point and 50 feet (15 m) at its deepest. The amount of time between impact and collapse allowed everyone on the fourth and fifth levels to evacuate safely before the structure collapsed. After the collapse, the interior fires intensified, spreading through all five floors. After 11:00, firefighters mounted a two-pronged attack against the fires. Officials estimated temperatures of up to 2,000 °F (1,090 °C). While progress was made against the interior fires by late afternoon, firefighters realized a flammable layer of wood under the Pentagon's slate roof had caught fire and begun to spread. Typical firefighting tactics were rendered useless by the reinforced structure as firefighters were unable to reach the fire to extinguish it. Firefighters instead made firebreaks in the roof on September 12 to prevent further spreading. At 18:00 on the 12th, Arlington County issued a press release stating the fire was "controlled" but not fully "extinguished". Firefighters continued to put out smaller fires that ignited in the succeeding days.
Various pieces of aircraft debris were found within the wreckage at the Pentagon. While on fire and escaping from the Navy Command Center, Lt. Kevin Shaeffer observed a chunk of the aircraft's nose cone and the nose landing gear in the service road between rings B and C.  Early in the morning on Friday, September 14, Fairfax County Urban Search and Rescue Team members Carlton Burkhammer and Brian Moravitz came across an "intact seat from the plane's cockpit",  while paramedics and firefighters located the two black boxes near the punch out hole in the A-E drive, nearly 300 feet (91 m) into the building.  The cockpit voice recorder was to retrieve any information, though the flight data recorder yielded useful information.  Investigators also found a part of Nawaf al-Hazmi's driver's license in the North Parking Lot rubble pile.  Personal effects belonging to victims were found and taken to Fort Myer. 
Army engineers determined by 5:30 p.m. on the first day that no one remained alive in the damaged section of the building. In the days after the crash, news reports emerged that up to 800 people had died.  Army soldiers from Fort Belvoir were the first teams to survey the interior of the crash site and noted the presence of human remains. Federal Emergency Management Agency (FEMA) Urban Search and Rescue teams, including Fairfax County Urban Search and Rescue assisted the search for remains, working through the National Interagency Incident Management System (NIIMS).  Kevin Rimrodt, a Navy photographer surveying the Navy Command Center after the attacks, remarked that "there were so many bodies, I'd almost step on them. So I'd have to really take care to look backwards as I'm backing up in the dark, looking with a flashlight, making sure I'm not stepping on somebody". Debris from the Pentagon was taken to the Pentagon's north parking lot for more detailed search for remains and evidence.
Remains that were recovered from the Pentagon were photographed, and turned over to the Armed Forces Medical Examiner office, located at Dover Air Force Base in Delaware. The medical examiner's office was able to identify remains belonging to 179 of the victims.  Investigators eventually identified 184 of the 189 people who died in the attack.  The remains of the five hijackers were identified through a process of elimination, and were turned over as evidence to the Federal Bureau of Investigation (FBI). On September 21, the ACFD relinquished control of the crime scene to the FBI. The Washington Field Office, National Capital Response Squad (NCRS), and the Joint Terrorism Task Force (JTTF) led the crime scene investigation at the Pentagon. 
By October 2, 2001, the search for evidence and remains was complete and the site was turned over to Pentagon officials. In 2002, the remains of 25 victims were buried collectively at Arlington National Cemetery, with a five-sided granite marker inscribed with the names of all the victims in the Pentagon. The ceremony also honored the five victims whose remains were never found.
At around 3:40 a.m. on September 14, a paramedic and a firefighter who were searching through the debris of the impact site found two dark boxes, about 1.5 feet (46 cm) by 2 feet (61 cm) long. They called for an FBI agent, who in turn called for someone from the National Transportation Safety Board (NTSB). The NTSB employee confirmed that these were the flight recorders ("black boxes") from American Airlines Flight 77.  Dick Bridges, deputy manager for Arlington County, Virginia, said the cockpit voice recorder was damaged on the outside and the flight data recorder was charred. Bridges said the recorders were found "right where the plane came into the building." 
The cockpit voice recorder was transported to the NTSB lab in Washington, D.C., to see what data was salvageable. In its report, the NTSB identified the unit as an L-3 Communications, Fairchild Aviation Recorders model A-100A cockpit voice recorder—a device which records on magnetic tape. No usable segments of tape were found inside the recorder; according to the NTSB's report, "[t]he majority of the recording tape was fused into a solid block of charred plastic". On the other hand, all the data from the flight data recorder, which used a solid-state drive, was recovered. 
Continuity of operations
At the moment of impact, Secretary of Defense Donald Rumsfeld was in his office on the other side of the Pentagon, away from the crash site. He ran to the site and assisted the injured. Rumsfeld returned to his office, and went to a conference room in the Executive Support Center where he joined a secure videoteleconference with Vice President Dick Cheney and other officials. On the day of the attacks, DoD officials considered moving their command operations to Site R, a backup facility in Pennsylvania. Secretary of Defense Rumsfeld insisted he remain at the Pentagon, and sent Deputy Secretary Paul Wolfowitz to Site R. The National Military Command Center (NMCC) continued to operate at the Pentagon, even as smoke entered the facility.  Engineers and building managers manipulated the ventilation and other building systems that still functioned to draw smoke out of the NMCC and bring in fresh air.
During a press conference held inside the Pentagon at 18:42, Rumsfeld announced, "The Pentagon's functioning. It will be in business tomorrow."  Pentagon employees returned the next day to offices in mostly unaffected areas of the building. By the end of September, more workers returned to the lightly damaged areas of the Pentagon.
Early estimates on rebuilding the damaged section of the Pentagon were that it would take three years to complete. However, the project moved forward at an accelerated pace and was completed by the one-year anniversary of the attack.  The rebuilt section of the Pentagon includes a small indoor memorial and chapel at the point of impact. An outdoor memorial, commissioned by the Pentagon and designed by Julie Beckman and Keith Kaseman, was completed on schedule for its dedication on September 11, 2008.  Since September 11, American Airlines continues to fly from Dulles International Airport to Los Angeles International Airport. As of August 2016, flight number 77 has been renumbered to 2636, now using a Boeing 737-800, departing at 7:40 in the morning. 
Security camera video
The Department of Defense released filmed footage on May 16, 2006, that was recorded by a security camera of American Airlines Flight 77 crashing into the Pentagon, with a plane visible in one frame, as a "thin white blur" and an explosion following.  The images were made public in response to a December 2004 Freedom of Information Act request by Judicial Watch.  Some still images from the video had previously been released and publicly circulated, but this was the first official release of the edited video of the crash. 
The Doubletree Hotel, located nearby in Crystal City, Virginia, also had a security camera video. The FBI released the video on December 4, 2006, in response to a FOIA lawsuit filed by Scott Bingham. The footage is "grainy and the focus is soft, but a rapidly growing tower of smoke is visible in the distance on the upper edge of the frame as the plane crashes into the building". 
On September 12, 2002, Defense Secretary Donald Rumsfeld and General Richard Myers, Chairman of the Joint Chiefs of Staff, dedicated the Victims of Terrorist Attack on the Pentagon Memorial at Arlington National Cemetery.  The memorial specifically honors the five individuals for whom no identifiable remains were found. This included Dana Falkenberg, age three, who was aboard American Airlines Flight 77 with her parents and older sister. A portion of the remains of 25 other victims are also buried at the site.  The memorial is a pentagonal granite marker 4.5 feet (1.4 m) high. On five sides of the memorial along the top are inscribed the words "Victims of Terrorist Attack on the Pentagon September 11, 2001". Aluminum plaques, painted black, are inscribed with the names of the 184 victims of the terrorist attack. The site is located in Section 64, on a slight rise, which gives it a view of the Pentagon.
The Pentagon Memorial, located just southwest of The Pentagon in Arlington County, Virginia, is a permanent outdoor memorial to the 184 people who died as victims in the building and on American Airlines Flight 77 during the September 11 attacks.  Designed by Julie Beckman and Keith Kaseman of the architectural firm of Kaseman Beckman Advanced Strategies with engineers Buro Happold,  the memorial opened on September 11, 2008, seven years after the attack.
Nationalities of people on the plane
Note: This list does not include the nationalities of the five hijackers.