One-way tickets to hell
From the moment the hijackers boarded their aircraft to the struggle of survivors emerging from the rubble, Matthew Moore and Stephanie Peatling track the hours of horror.
· Pop-up graphic: How the destruction unfolded
Amanullah Atta Mohammed's early flight from Portland, Maine, arrived at Logan International Airport, Boston, just in time for him to connect with American Airlines flight 11 to Los Angeles, but too late for his luggage to be loaded.
By 7.45am on Tuesday the 33-year old Saudi national, and trained commercial aircraft pilot, had walked through the departure gate, down the loading ramp and a few steps down the plane's aisle on his way to seat 8D in business class on the Boeing 767.
He would not have known that two suitcases bearing his name tags had been left behind, one containing a Saudi passport, an international driver's licence, a religious cassette tape and a videotape on how to fly a Boeing 757 and 747.
Mohammed was seated directly across the aisle from David Angell, an executive producer of the television comedy Frasier, along with his wife, Lynn. They were in seats 8A and 8B respectively. Next to Mohammed in seat 8G was his friend Abdul Alomari.
American Airlines flight 11 left Logan right on time at 7.59am, but it stayed on course, almost due west, for only 16 minutes. Instead of taking a southerly turn, the Boeing 767 swung to the north at 8.15am. Hijackers had taken over their first aircraft.
By then all four doomed aircraft were in the air. Terrorist crews were on board United Airlines flight 93, from Newark, New Jersey, bound for San Francisco, American Airlines flight 77 from Washington's Dulles Airport, bound for Los Angeles, and UA Flight 175, again from Logan, and again bound for Los Angeles.
On flight 175 was Marwan Alshehri. Like Mohammed, he was trained to fly heavy commercial aircraft, as was his brother, Waleed Alshehri, who is reported to have been on the same flight. It is almost certain Marwan Alshehri was travelling on one of five one-way tickets bought at the last minute by hijackers for flight 175, four of them bought with one Visa card.
Both may have been among the two or more hijackers who are believed to have spent Monday night in room 432 of the Park Inn in Chestnut Hill, Boston, where the FBI found airline and train schedules.
Investigators have traced Marwan Alshehri to a rented Mitsubishi sedan found in the car park at Logan airport on Tuesday. Videotape from the airport's surveillance cameras has shown that the car went to the airport up to five times in the six days before the attacks.
Found in the car was a pass that gave the holder access to restricted areas at Logan.
US airlines maintain a computerised checklist of about 25 factors that are weighed in determining whether an individual subjected to special scrutiny, including whether they bought at the last minute, if the ticket is one way or was bought by someone from an Arab background. But neither Marwan Alshehri nor the other 11 men with Arabic surnames on the American and United flights received any special attention, leaving one State official dismayed. "That is something that should jump out at you. One-way ticket, purchased by Arabic gentlemen; that should have been red-flagged.''
Also unnoticed was the fact that most of these men carried blades in their hand luggage.
It was about 8.15am on flight 11 when the blades came out. Mohammed, Alomari and at least one other man leapt from their seats and either slashed or threatened one or more flight attendants with Stanley knives.
Five minutes later, at 8.20am, flight 11 failed to follow an instruction to climb to its cruising altitude of 31,000 feet. It was then that air controllers knew something was wrong, and when the aircraft's transponder, a piece of equipment that broadcasts its location, went out.
In the cabin, one flight attendant made a telephone call either on a mobile phone or on a phone on the back of a seat to the American Airlines operations centre, warning that a hijacking was in progress and giving
the seat number of one of the hijackers.
The captain, John Ogonowski, 50, tried to signal air controllers by "keying" the microphone, pushing its button intermittently to signal that something was wrong. It allowed them to hear the voice of one of the hijackers. "Don't do anything foolish; you won't be hurt ... We have more planes. We have other planes."
There was nothing they could do. The hijackers took the aircraft lower and headed for New York.
On the streets of Manhattan people looked up as the plane screamed 300 metres above.
In the Windows on the World restaurant on the 107th floor of the north tower of the World Trade Centre, dozens of businessmen were enjoying a leisurely breakfast and the spectacular view when flight 11 slammed into the building 20 floors below. It was 8.48am.
By then, the three other planes were doomed.
Somebody turned flight 77's transponder off just after it headed west into Ohio. Presumably, that was when the hijacking happened, about the time flight 175 was rapidly closing on the south tower of the flaming World Trade Centre.
On flight 93 one person had been stabbed to death by hijackers that passenger Jeremy Glick described to his wife as "three Arab-looking men with red headbands", carrying a knife and talking about a bomb.
Marwan Alshehri's crew had already slashed or stabbed flight attendants on flight 175. In several brief calls to his father, Peter Hanson, 32, said hijackers were trying to force the crew to open the cockpit doors. "The plane is going down," he told his father. His wife and two-year-old daughter were with him.
When flight 11 smashed into the north tower of the World Trade Centre Louis Lesce was sitting in his office on the 86th floor, reviewing some work.
"I felt it was an earthquake, and it didn't bother me because I felt the building could sustain earthquakes.
"Then there was a huge explosion and the ceiling fell. I got out of that conference room, and there were five other people on the floor and we decided to leave, but when we opened the door there was a wall of black smoke."
Sitting in the office, Mr Lesce and his colleagues tried to be calm as they discussed their options. "We decided to break the windows, and one of the gentlemen found a ball-peen hammer ... We had no alternative so we broke the window, and at that point glass flew in as well as hot shrapnel."
About 20 minutes later the group decided to walk down the stairwell to escape the building.
Screaming and sirens were all they could hear as they made their way down the crowded stairwell. "There were people passing me bruised and bleeding and some people being carried down," Mr Lesce said. "But what was marvellous is, we were on the right side and here were firemen carrying maybe 30, 40 pounds of load going upstairs. Where we were trying to escape, they were going to it."
When the first jet struck it gave those across on the south tower an unparalleled view of the destruction and a clear sign of what they had to do: get out fast.
Katherine Ilachinski, an architect working on the 91st floor of the south tower, went for the stairs - despite her 70 years.
But others up and down the 110 floors, many without clear views of the damage across the way, were not so sure. And the 15 minutes before the next aircraft would hit were ticking off.
Amid the uncertainty about what was the best thing to do, announcements inside the south tower instructed people to stay put, reassuring them that the building was sound and the threat was limited to the other tower. Some began the climb down, and when they heard more announcements and other cautions to stop or return, went back up.
Richard Jacobs, of Fuji Bank USA, left the 79th floor with all of his colleagues, but on the 48th floor they heard the announcement that the situation was under control. Several got in the elevators and went back up, two minutes or so before the plane smashed into their floor. "I just don't know what happened to them," Mr Jacobs said.
Morgan Stanley worker Arturo Domingo said the descent from the south tower had been calm and orderly, much better than after the bomb blast at the building in 1993. But when he reached the 44th floor, a man with a megaphone told people there was no problem.
"His exact words were, 'Our building is secure. You can go back to your floor. If you're a little winded, you can get a drink of water or coffee in the cafeteria," Mr Domingo said. He and a group of other Morgan Stanley employees rode a lift back up to the 60th floor and returned to their desks. "How stupid were we?" he said.
When the second plane hit, just above his floor, he headed for the exit again and passed the same man with the megaphone, now assuring people they would get out alive.
While New York was reeling from jet crashes, flight 77, at 9.40am, slammed into the
Lieutenant Colonel Robert Grunewald, who worked in the Army's Bureau of Personnel and barely survived the attack, had been at a routine 9am meeting when the sudden carnage and wreckage began. "Flames came shooting out of the wall and the ceiling started coming down on top of us," Colonel Grunewald said from a hospital bed..
Colonel Roy Wallace, the chief of the resources division in the same department, described a slow-motion evacuation and how he helped carry an army officer out of churning smoke that "was rolling like a wave".
Ten minutes after the Pentagon was hit, Mr Lesce and his associates were huddled in the foyer of the World Trade Centre - they could hear rumbling around them.
"I turned around and ... the building was collapsing and the next thing was this huge rush of wind pushing me. I fell down immediately and hugged the ground and debris went over my head and just buried me."
Among those killed when the towers collapsed were three of the Fire Department's most senior officials - William Feehan, the first deputy commissioner, Peter Ganci, the chief of department, and Raymond Downey, the chief of special operations, who were directing rescue operations from a command post near Vesey and West streets.
About 350 firefighters had entered the north tower after the first plane crashed, including Captain Timothy Stackpole who was off duty when he heard about the terrorist attack but had gone to the Trade Centre to help, officials later said.
At Engine Company 1 in Manhattan, firefighters recalled how they got out of the north tower when they were told the south tower had just collapsed. Their lieutenant, Andy Desperito, told them to get out, while he stopped to help someone. Several minutes later, they were on the street, when the north tower fell. Lieutenant Desperito's body was recovered later in the day.
After what seemed like hours Mr Lesce could see a tiny prick of light. It grew until a body appeared and helped him out.
He and his colleagues thought they were in an underground passage created by the rubble. Eventually they found a policeman who directed them to what looked like a door.
"It was really broken glass and the man went through and I went about 20 feet behind him and he disappeared. And that was the eerie thing. All these people I was with disappeared. When I stepped out into the plaza, there was nobody. It was like the last man on earth and everywhere there was about four inches of white soot that looked like snow.''
As Mr Lesce started to think about how he could contact he wife, he heard a familiar sound.
It was just before 10.30am and the north tower, where he had begun his day only hours before, had collapsed.
"This black roar came back again and turned the day absolutely black. I threw myself on the ground and waited a second time for the blackness to stop. And finally again there was a little pin of light and somebody's voice asking me to stand up.''
Mr Lesce walked. At first he went in to a shop where someone gave him a T-shirt to wear.
He headed for Beekmad Hospital but police turned him back. Instead he was treated at a triage centre before finally making contact with his wife.
Flight 93 disintegrated in Pennsylvania field, with last radar contact recorded at 10.03am - 25 minutes before it was scheduled to arrive in Washington.
Additional reporting by agencies