AP National WriterNEW YORK (AP) -- Shortly before 8 a.m. Tuesday, American Airlines Flight 11 left Boston for Los Angeles. It would not reach its destination.
Something happened shortly after takeoff. A hijacking. And instead of climbing well aloft and heading west, the plane swept to the south, to New York.
Clyde Ebanks, vice president of an insurance company, was at a meeting on the 103rd floor of the South Tower of the World Trade Center when his boss said, "Look at that!"
He turned and through a window saw a plane go by and hit the other building.
It was 8:50 a.m.
For Peter Dicerbo and 44 co-workers at First Union National Bank, it was the start of their workday -- a beautiful day, with sunlight glinting off the Hudson River and streaming though the windows on the 47th floor of the trade center.
And then, "I just heard the building rock. It knocked me on the floor. It sounded like a big roar, then the building started swaying, that's what really scared me."
Harriet Grimm, inside the Borders bookstore on the trade center's first floor, heard a large boom, "and then we saw all this debris just falling."
About 18 minutes later, Luigi Ribaudo -- who works nearby, in Tribeca -- heard a twin-engine plane making what he said was a strange noise. He looked up; he saw a plane that was "too low."
"It was going to hit something and it hit and exploded inside," he said. It was American Flight 77, a Boeing 757, operating from Washington Dulles to Los Angeles.
Two towers, two direct hits.
The chaos was immediate.
Dicerbo led his 44 colleagues down 47 flights of stairs, He staggered away from the building, his clothes torn; the workers were stunned, dazed and coughing.
"The minute I got out of the building, the second building blew up," said Jennifer Brickhouse, 34, from Union, N.J., who was going up the escalator into the World Trade Center when she "heard this big boom."
"All this stuff started falling and all this smoke was coming through. People were screaming, falling, and jumping out of the windows," from high in the sky.
Emergency vehicles flooded into lower Manhattan. No one knew what happened; the towers, target of a terrorist bombing in 1993, seemed to be ground zero once again.
About 9:30 a.m., an aircraft crashed at the Pentagon in Washington. The nerve center of the nation's military burst into flames and a portion of one side of the five-sided structure collapsed, sending billows of smoke over the capital.
At 9:50 a.m. -- an hour after the first crash -- One World Trade Center collapsed.
There was a strange sucking sound, and then the sound of floors collapsing, and then an incredible surge of air, followed by a vast cloud of dirt, smoke, dust, paper and debris. Windows shattered. People screamed and dived for cover.
Around 10 a.m., a United Airlines flight from Newark to San Francisco crashed 80 miles southeast of Pittsburgh.
Government buildings around the country began to be evacuated, including the Capitol and the White House. The Federal Aviation Administration stopped all takeoffs nationwide. The United Nations closed down. In New York, the tunnels and bridges were closed.
At exactly 10:30 a.m., the second tower of the World Trade Center collapsed.
The top of the building exploded with smoke and dust. There were no flames, just an explosion of debris and dust and smoke, and then more huge vast clouds swept down to the streets. People were knocked to the ground onto their faces as they were running from the building toward cover. And then the same huge clouds of smoke, dust and debris and came through the buildings and blocked out the sun.
At noon, United Airlines announced that another of its planes had gone down. No location was given; it was not confirmed whether this was the plane that hit the Pentagon.
"I just can't believe what's happened. God, my heart goes out to all of these people, believe me. I just hope there is justice," said Martha Ridley, whose daughter died in the April 1995 Oklahoma City bombing.