Some city officials, including former Mayor Rudolph Giuliani, have suggested some firefighters ignored the mayday call in acts of personal heroism. But the group of families has sought to lay blame on the city for providing firefighters with faulty radios.
Firefighter Paul Bessler recalled a colleague storming up the north tower's stairs as if he was ''on a mission.''
''Just at that point, my radio came clear as day, 'Imminent collapse. This was a terrorist attack. Evacuate.'''
But Thomas Piambino said he heard ''absolutely nothing'' ordering him out of the tower.
He and others nearby left the tower before it fell, but he said he did not know why.
''It was just _ I don't know what it was,'' he said. ''It was just the culmination of intuition or what. I just decided it was time to go.''
The transcripts reinforce the perception that some firefighters throughout the trade center dropped protocol and simply acted according to their best instincts.
Firefighter Patrick Martin of Engine 229 said that after the south tower had collapsed and before the north tower came down, his lieutenant ordered him to a boat taking people to hospitals across the Hudson River.
''I told him I wasn't leaving,'' Martin said. ''We were still missing one guy.''
The oral histories underscored the small, even random, decisions that separated those who lived from those who died.
Firefighter George Rodriguez remembered sheltering with about 30 civilians in the lobby of 7 World Trade Center. Two of them wanted to get out because of heavy smoke and ash. Firefighters tried to keep them inside, but the pair eventually ran out.
''Unfortunately for them they ran to the left, which happened to be right towards Vesey Street, which was the wrong way to go,'' Rodriguez said. ''I never saw those two again.''
Sept. 11 family members pored over the records Friday, some tearing up at the descriptions and sounds.
''It's very emotional. It's very difficult,'' said Sally Regenhard, mother of 28-year-old Christian Regenhard, killed along with most of his company's firefighters that day. ''But it's no harder than knowing every day that my son is gone.''
The New York Times and families of Sept. 11 victims sued the city in 2002 to release the records, which were collected by the Fire Department in the days after the collapse of the twin towers.
The city withheld them, but in March, the state's highest court ordered release of the records, allowing the city to leave out potentially painful and embarrassing portions. Portions of 911 calls have yet to be released.
The Fire Department, in a statement, said it hoped the release of the records would not cause firefighters and their families additional pain.
''The Department believes that the materials being released today ... will serve to further confirm the bravery and courage of our members who responded to the World Trade Center,'' the statement said.