On Tuesday, September 11, 2001 at 8:50 a.m. is the last normal radio communications from American Airlines Flight 77 to air traffic control.
At 8:54 a.m., the plane began to deviate from its normal, assigned flight path and turned south.
At 8:56 a.m., the plane's transponder was switched off.
The pilots had been shoved to the back of the plane with the rest of the passengers. 
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.
The FAA was aware at this point that there was an emergency on board the airplane.
Flight 11 had already crashed into the North Tower of the World Trade Center and Flight 175 was known to have been hijacked.
Gerard Arpey had already ordered a nationwide ground stop for the airline.
Flight 77 was flying over an area of limited radar coverage and air controllers unable to contact the flight by radio.
At 9:12 a.m., flight attendant Renee May made a two minute call to her mother in Las Vegas.
May said her flight was being hijacked by six people, and staff and passengers had been moved to the rear of the airplane.
May asked her mother to contact American Airlines, which she did.
Between 9:16 a.m. and 9:26 a.m., passenger Barbara Olson called her husband and reported that the airplane had been hijacked and that the assailants had box cutters and knives.
She said that the passengers and 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.
Five minutes later, Barbara Olson called again, told her husband that the "pilot" had announced on the intercom, the flight was hijacked, and asked,
"What do I tell the pilot to do?"
Her husband 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 and then the call cut off again.
Dulles International Airport Air traffic controller, Danielle O'Brien stated,
"The speed, the maneuverability, the way that he turned, we all thought in the radar room, all of us experienced air traffic controllers, that that was a military plane.
You don't fly a 757 in that manner.
It's unsafe."
An airplane was detected again by Dulles controllers on radar screens as it approached Washington, turning and descending rapidly.
Controller 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.
He said 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 assumed it had hit the ground. As he approached 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."
At 9:37 a.m., Flight 77 had crashed into the west side of Pentagon, not before knocking over five street lampposts with it's wings.
The right wing also struck a portable generator, creating a smoke trail.
The plane hit the Pentagon at the first-floor level.
At the moment of impact, the airplane was rolled slightly to the left, with the right wing elevated. and the front part of the fuselage disintegrated on impact.
The mid and tail sections moved for another fraction of a second, with tail section debris penetrating furthest into the building.
The airplane took eight-tenths of a second to fully penetrate 310 feet into the three outermost of the building's five rings.
It unleashed a fireball that rose 200 feet above the building.
18,000 people worked in the Pentagon and the section that was struck, which had recently been renovated at a cost of $250 million, housed the Naval Command Center.
125 die in the Pentagon building in addition to the 64 that died 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 two National Geographic Society staff members were also on board.
They were on an educational trip west to the Channel Islands National Marine Sanctuary near Santa Barbara, California.
Of those 125 killed, 92 were on the first floor, 31 were on the second floor, and two were on the third.
Another 106 were injured on the ground and were treated at area hospitals.
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, was cutting the grass on the other side of the road when the airplane flew over his head.
Later he said,
"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 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.
USA Today reporter Mike Walter was driving on Washington Boulevard when he witnessed the crash.
"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 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 is a pilot himself, noticed American Airlines markings on the aircraft as he saw it hit the Pentagon.
Former Georgetown University basketball coach John Thompson had originally booked a ticket on Flight 77.
He had been scheduled to appear on Jim Rome's radio show, on September 12, 2001.
Thompson was planning to be in Las Vegas for a friend's birthday on September 13.
He initially insisted on traveling to Rome's Los Angeles studio on the 11th, however, this did not work for the show.
Thompson changed his travel plans.
He felt the impact from the crash at his home near the Pentagon.
Rescue efforts were initially led by the military and civilian employees within the building.
The first fire companies arrived and found these volunteers searching near the impact site and ordered them to leave as they were not properly equipped or trained to deal with the hazards.
Firefighters from Fort Myer and Reagan National Airport arrived within minutes.
Rescue and firefighting efforts were impeded by rumors of additional incoming planes.
Two evacuations were ordered during the day in response to these rumors.
One firefighter remarked that they "pretty much knew the building was going to collapse because it started making weird sounds and creaking".
At 10:10 a.m., the upper floors of the damaged area of the Pentagon collapsed.
The amount of time between impact and collapse allowed everyone on the fourth and fifth levels to evacuate safely before the structure collapsed.
The interior fires intensified, spreading through all five floors.
After 11:00, officials estimated that the temperatures reached up to 2,000 °F
Progress was made against the interior fires by late afternoon.
A flammable layer of wood under the Pentagon's slate roof had caught fire and begun to spread.
Firefighters were unable to reach the fire to extinguish it, so instead they made firebreaks in the roof on September 12 to prevent further spreading.
Firefighters continued to put out smaller fires that ignited in the succeeding days
Lt. Kevin Shaeffer was on fire as he was escaping the Navy Command Center.
He observed a chunk of the aircraft's nose cone and the nose landing gear in the service road between rings B and C.
On the morning of 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".
Paramedics and firefighters located the two black boxes nearly 300 feet into the building near the punch out hole in the A-E drive.
The cockpit voice recorder was too badly damaged retrieve any information.
The flight data recorder did yield useful information.
A part of Nawaf al-Hazmi's driver's license was found by investigators in the North Parking Lot rubble pile.
Personal effects belonging to victims were found and taken to Fort Myer.
By 5:30 p.m. on the first day, it was surmised that no one remained alive in the damaged section of the building.
In the days after the crash, it was reported that up to 800 people had died.
A Navy photographer surveying the Navy Command Center after the attacks, remarked
"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 north parking lot for more detailed search for remains and evidence.
Remains that were recovered 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.
Eventually 184 of the 189 people who died in the attack were identified by investigators.
The remains of the five hijackers were identified through a process of elimination, and were turned over as evidence to the FBI.
By October 2, 2001, the search for evidence and remains was complete.
In 2002, the remains of 25 victims were buried together 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.
