We already know the names of hundreds of the victims of Tuesday's horrendous attacks: the crew and passengers of the four planes that went down. Here are some of their stories.
Barbara Olson, Prosecutor and Commentator
Barbara Olson, a former federal prosecutor and the wife of U.S. Solicitor General Ted Olson, died on board American Airlines Flight 77, the plane that crashed into the Pentagon.
I remember Barbara very well. She was a very vibrant figure, with a great deal of zest. Many people knew her because she was on cable television a great deal as a commentator.
Her husband is perhaps the best-known government figure to have suffered a loss in the attacks.
The Olsons had a very close marriage. Barbara had called her husband just before her plane took off from Virginia's Dulles airport, bound for Los Angeles. He was horrified when he heard news that a California-bound airliner had smashed into the World Trade Center, but was relieved to know that his wife was not onboard.
A short time later, however, she called him from her cell phone and said, "I'm on the plane and the plane is being hijacked." Then they were cut off.
He alerted the Justice Department command center immediately, then got his wife back on the line. She told him the hijackers were armed with knives and had herded the passengers to the back of the plane. She was very calm, he said.
Hoping to get a clue of where the plane was heading, Ted asked his wife if she could describe the ground she saw through the window.
She said, "All I see are buildings," and then the call abruptly ended.
David Angell, Television Producer
David Angell, one of the creators of the shows Cheers and Frasier, died with his wife Lynn on board American Airlines Flight 11, which crashed into the first World Trade Center tower.
Angell, 54, was perhaps the best-known of the victims who have been identified. I talked about him with Bebe Neuwirth, who played Lilith on Cheers.
"He was a quiet man, and my picture of him is a very, quiet strong presence," Neuwirth told me. She said he was "deeply intelligent and deeply funny," and a brilliant television producer who understood how to "talk up to the audience instead of down to the audience."
Neuwirth herself seemed close to tears during our interview. "It's been so hard to wrap my mind around the whole event," she told me, "This just was another surreal moment and it's devastating."
Christopher Newton, Business Executive
Christopher Newton, 38, was a business executive who died on American Airlines Flight 77. He traveled frequently on business, and had recently moved his family to Arlington, Va. so he could spend more time with them. He was on his way to California to pick up the family's yellow Labrador, Peter.
A Little League coach and a Cub Scout leader, he is survived by his wife and two children, Michael, 10, and Sarah, 7.
Alfred Marchand, Flight Attendant
Alfred Marchand was a flight attendant on United Airlines Flight 175, which crashed into the second World Trade Center tower.
Marchand, 44, was married with a son and two stepsons. After 17 years as a police officer and a fireman, he had recently embarked on a career change as a flight attendant. He told friends and family he wanted to "join the friendly skies."
His fellow officers say he was enthusiastic, and believe he would have reacted like a police officer when the hijackers took over the plane. No one knows for sure what happened onboard the plane.
Thomas Burnett Jr., Business Executive
Thomas Burnett, senior vice president and chief operating officer of medical device manufacturer Thoratec, was on United Airlines Flight 93 when it crashed in western Pennsylvania.
Burnett, 38, called his wife Deena from his cell phone. He told her that the flight was doomed and that one passenger had already been stabbed to death. But he said that he and two other passengers were going to, in his words, "do something about it."
His last words to his wife were, "I love you."