New York City has released new tapes of phone calls and other transcripts of people trapped inside the World Trade Center on 11 September 2001.
Hundreds of people were trapped in the south tower
They feature the last phone call of Melissa Doi as she is running out of air on the south tower's 83rd floor.
Families of some victims gathered to listen to the tapes, which were recently found by the Fire Department of New York.
Victims' relatives and the New York Times sued for the tapes' release.
In the tape, Melissa Doi, a 32-year-old financial manager, can be heard asking the emergency operator not to hang up: "Can you stay on the line with me, please? I feel like I'm dying."
She also says: "I'm going to die, aren't I?"
"No, no, no, no, no," responds the operator. "Ma'am, say your prayers. You've got to think positive because you've got to help people get off the floor."
The operator stays on the line for almost half an hour, urging Doi to keep breathing, even when her voice is no longer heard.
In the end, one dispatcher says: "The line is now dead."
"Oh my lord," says the operator.
Most of the calls released involved firefighters and dispatchers.
Calls made by 10 civilians inside the World Trade Center were edited out to protect citizens' privacy.
Relatives and the New York Times wanted to see whether the calls would reveal what happened inside the towers and whether operators misdirected the victims.
"We need to have the truth. We need to save other mothers' sons... Allow us to learn from the deadly mistakes of the past, so we can help people in the future," Sally Regenhard, whose son - a firefighter - was killed, is quoted as saying by Reuters news agency.
A portion of Doi's end of the conversation was played for jurors in April at the trial of 11 September conspirator Zacarias Moussaoui, but this was the first time the operator's voice was heard.
"Are they going to be able to get somebody up here?" Doi asks.
"Of course ma'am, we're coming up for you," the operator replies.
"Well, there's nobody here yet and the floor is completely engulfed. We're on the floor and we can't breathe and it's very, very, very hot."
In March, the city released transcripts of 130 calls from people trapped in the towers, including only the voices of operators and other public employees.
The New York Times initially sought the records in 2002 under the Freedom of Information Act, and later sued the city when it refused to release them.