"Then I yelled to Ronnie, I yelled up, because he was ahead of me -- I said, `Ronnie, I got to help her down, I'll be back,' " Mr. Devery said. "But he didn't answer me. He must have been two flights ahead of me."
Mr. Devery and Mrs. Young took the elevator on the 41st floor to the street. She spent weeks in the hospital recuperating.
When Chief Palmer reached the 75th floor, he reported meeting a fire marshal in the stairway, and officials said that was Mr. Bucca. The two men were well ahead of all the other firefighters in the building. Mr. Bucca, 47, was very fit, like Chief Palmer, and was active in the Army Reserve.
As they passed other survivors from the impact zone, Chief Palmer informed the fire officers on the lower floors about their injuries. Chief Geraghty, who had come to the 41st floor, called down to the ground for firefighters with medical training.
Chief Palmer also found an obstruction in the stairway and told the trailing fire companies how to get around it. He asked the chiefs below him to find an elevator that reached the 76th floor, those who heard the tape said.
Throughout, the voices of Chief Palmer, Chief Geraghty, and the other firefighters showed no panic, no sense that events were racing beyond their control.
When Chief Palmer radioed from the 78th floor, he sounded slightly out of breath, perhaps from exertion or perhaps from the sight of all the people who moments before had been waiting for an elevator and now were dead or close to it.
"Numerous 10-45's, Code Ones," Chief Palmer said, using the Fire Department's radio terms for dead people.
At that point, the building would be standing for just a few more minutes, as the fire was weakening the structure on the floors above him. Even so, Chief Palmer could see only two pockets of fire, and called for a pair of engine companies to fight them.
Among those lying in the lobby of the 78th floor was Richard Gabrielle, an Aon employee who had been waiting for the elevator. He was trapped under marble that was blown off the wall, witnesses said.
His widow, Monica Gabrielle, said that she has been tormented by nightmares about her husband's last moments, and that she was appalled that fire officials had waited so long to listen to the tape. She had wondered whether her husband had died alone. The efforts of Chief Palmer and Mr. Bucca in reaching the 78th floor eased that anxiety.
"The fact that Rich, still alive, was not alone -- at least he knew there was help, and thought that they were getting out," she said. She added that she thought all such records should be made public.
Mrs. Palmer said that as she sat in the audience on Friday listening to the tape, she realized that she knew how events would end, but that her husband and the other firefighters did not. "In my mind, I was saying, hurry up, hurry up, get out of there," she said. "But what's done is done."