Trapped and running out of air on the smoky 83rd floor of the World Trade Center, Melissa Doi begged the emergency operator not to hang up. "Can you stay on the line with me, please? I feel like I'm dying," Doi said. The operator stayed on for 24 minutes, imploring Doi to keep breathing and praying, saying, "It's going to be fine" over and over, long after Doi had stopped talking. Finally, the connection ended. "The line is now dead," one dispatcher said. "Oh my lord," said the operator. Doi, a 32-year-old financial manager, died in the World Trade Center's south tower on Sept. 11, 2001. On Wednesday, her voice was heard as the city released new tapes of hundreds of heart-wrenching phone calls, along with other emergency transcripts. The tapes recorded rescuers complaining about chaos in the twin towers. But they also evoked the firefighters' powerful sense of duty, with some struggling to evacuate the towers and others begging dispatchers to send them to the scene. A total of 343 firefighters died in the disaster. "We're in a state of confusion," Battalion Chief Dennis Devlin said, standing inside a command post at the trade center as the towers burned above. "We have no cell phone service anywhere because of the disaster. ... Bring all the additional handy talkies." Devlin was one of 19 dead firefighters whose voices were captured on the 1,613 previously undisclosed emergency calls. The New York Times and relatives of Sept. 11 victims sued for release of the tapes to learn what happened in the towers and what dispatchers told workers and rescuers. Most of the calls involved firefighters and dispatchers. The voices of 10 civilians calling from inside the World Trade Center were edited out because of privacy concerns. A portion of Doi's end of the conversation was played for jurors in April at the trial of Sept. 11 conspirator Zacarias Moussaoui, but this was the first time the operator's voice was heard. Within minutes of the first plane hitting at 8:46 a.m., firefighters - some off-duty, some even retired - began calling dispatchers to volunteer their help. Lt. Timothy Higgins, in a typical response, called at 8:52 a.m. "We're available for the trade center," he volunteered. "OK, thanks," replied the dispatcher. Higgins, with five other members of his squad, made the trip to Manhattan. All six died. In the Bronx, Lt. Michael Healey called a dispatcher just before the second plane hit to ask for an assignment in lower Manhattan. "I was just seeing if he could maybe possibly get us over there, so, just keep us in mind, over into Manhattan," he said. "OK," the dispatcher said. They responded, with Healey and five other squad members killed. Devlin, in the lobby of the south tower, provided a glimpse of the problems. Thirty-five floors above, fire Capt. Patrick Brown reported a chaotic scene of civilians _ some with burn injuries _ going down the stairwell as firefighters headed into the fire. "Apparently it's above the 75th floor," Brown said in the 24-second exchange barely an hour before the north tower fell. "I don't know if they got there yet. We're still heading up." The same mix of concern and confusion was evident in other more frantic calls. "One of the towers just collapsed," said an unidentified fire lieutenant. "Everybody's got to be inside of it. ... There's got to be thousands of the people inside it. One of the towers just came down on top of everybody." One off-duty worker was in tears when she called in to try to report for duty. "All those people - what about the EMTs (emergency medical technicians) and paramedics and firefighters in there helping people get out?" she asked her supervisor. "I don't know, sweetie, I really don't know." "Oh God." Family members complained their loved ones were betrayed by poor communication that could have steered them outside before the buildings collapsed. "We're still looking for information for how we can fix what went wrong that day," said Aggie McCaffrey, whose firefighter brother Orio Palmer was killed when the first tower collapsed. Barbara Hetzel lost her son Thomas, a firefighter. Although she has listened to such tapes before, she said, it does not get easier with time. "It's even deeper and sadder," said Hetzel, who listened with less than a dozen family members in a midtown Manhattan high-rise. 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 callers' voices were cut out after city attorneys argued that their pleas for help were too emotional and intense to be publicized without their families' consent. Thousands of pages of emergency workers' oral histories and radio transmissions were released last August. Fire Commissioner Nicholas Scoppetta ordered his department to search for additional recordings when another tape turned up shortly after the March release.