The voices of firefighters who came to rescue people from the burning World Trade Center hold clues about what happened after jetliners struck the towers on Sept. 11, 2001 — but until now, many went unheard.

On Wednesday, city officials planned to publicly play voices recorded on hundreds of emergency calls for the first time. They are among 1,613 previously undisclosed emergency calls recently discovered by city officials.

The Fire Department said the calls were discovered after the city turned over more than 100 dispatches in March under a court order. Most of the calls are from firefighters asking dispatchers where they should report for duty, the department said.

The New York Times and families of Sept. 11 victims sued for access to the emergency calls and firefighters’ oral histories. Attorneys said they wanted to find out what happened in the towers after two hijacked jetliners crashed into them and what dispatchers told workers and rescuers in and around the buildings.

Attorney Norman Siegel, who represents Sept. 11 families, called on Mayor Michael Bloomberg to pledge that no more emergency recordings from that day exist.

“We need the mayor to assure the family members that this is it, that this is everything we have,” Siegel said. “If it was 10 or 20 tapes, one could understand that they overlooked some. But if you’re talking hundreds, and possibly as many as 2,000 tapes, the serious substantial question is how did this happen?”

A spokesman for the mayor declined to comment Tuesday.

The city in March 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.

Fire Commissioner Nicholas Scoppetta ordered his department to search for additional recordings when another tape turned up shortly after the March release of 911 calls. City officials listened to all calls to emergency and fire dispatchers between 8:45 a.m. and 10:45 a.m. on Sept. 11 to locate all available recordings.

The fire department said Tuesday that when it first turned over its emergency calls, officials “misinterpreted instructions they were given on what kinds of calls to copy” and “failed to capture” other 911 calls they knew had to be made public.

“The department regrets the delay,” it said in a statement.

The calls include 10 made by people trapped in the twin towers, although those will include only the voices of the operators who heard their pleas. Also, 19 of the 343 firefighters who died, along with two emergency medical technicians, identify themselves to dispatchers.

The city planned to play the remainder of the call — with only the operator’s voice — of Melissa Doi, who spent more than 20 minutes on the phone with a 911 operator from the 83rd floor of the south tower before she was killed. Excerpts of Doi’s side of the conversation were played for jurors in April at Sept. 11 conspirator Zacarias Moussaoui’s trial.

“I’m going to die, aren’t I?” Doi asked the dispatcher. “Please God, it’s so hot. I’m burning up.”

Copyright © 2006 The Associated Press