The instructions to those trapped above where airliners had slammed into the World Trade Center on Sept. 11, 2001, sometimes sounded stern, sometimes sympathetic. But the central theme was the same: Stay put.
"We are trying to get up there, sir. Like you said, the stairs are collapsed, OK?" a fire dispatcher told one frantic caller trapped on the 105th floor of the south tower. "I know it's hard to breathe. I know it is."
The desperate attempts to calm callers' fears amid the chaos were revealed on several hours of 911 tapes released Friday as the result of a lawsuit. In many instances, dispatchers assured the callers on the upper floors that help was coming, or already there.
"OK, ma'am. All right," the same fire dispatcher told a caller at 9:05 a.m., two minutes after a plane hit the second tower. "Well, everybody is there now. We're trying to rescue everybody. OK?"
The tapes show that the dispatchers — some of them based at a distant facility in Central Park — struggled to keep pace with the furiously unfolding scene, and were slow to grasp that it was a choreographed terrorist attack involving two planes and both towers.
But emergency officials credited them on Friday with generally keeping their composure, and giving the right advice for high-rise tenants trapped by fires raging on lower floors.
"While today's release of 911 dispatch tapes brings back painful memories, it also clearly demonstrates that our dispatchers were unsung heroes on the darkest day in our city's history," Fire Commissioner Nicholas Scoppetta said in statement.
A small group of people who lost loved ones in the terrorist attacks gathered at a Manhattan law office to hear recordings of the 911 calls.
Sally Regenhard, whose son Christian, a firefighter, died in the attacks, said she believed more people would have survived if better information had been available to rescuers.
The knowledge that some callers died in the unexpected collapse of the towers severely traumatized those who had repeatedly told them to sit tight. Some dispatchers never came back to work after that day. Some retired early.
"Unfortunately, they took it very much to heart," said David Rosenzwieg, a dispatcher supervisor.
The 130 calls edited out the voices of those who sought help after terrorists flew the hijacked jets into the twin towers, but the police and fire dispatchers often repeated the callers' words, reflecting the chaos of the morning of the attack that killed 2,749 people at the trade center.
The voices of the fire and police operators who heard the calls for help were released after The New York Times and relatives of Sept. 11 victims sued to get them. An appeals court ruled last year that the calls of victims in the burning twin towers were too intense and emotional to be released without their families' consent.
The transcripts of the calls held long blank spaces where the callers' words would have appeared. Often, the operators talked to each other about trying, even as their computers crashed, to deal with the once-unimaginable situation.
"All right, we have quite a few calls," said a fire operator.
"I know," responded a police operator. "Jesus Christ."
Sirens screamed in the background as the callers pleaded for help. Although there were no voices, their desperation was evident in heavy, audible breathing on the other line of the operators' calls.
"If you feel like your life is in danger, do what you must do, OK?" one dispatcher told a caller at 9:02 a.m., just a minute before the second plane hit. "I can't give you any more advice than that."
The first transcripts released as part of the Times lawsuit came last August, when thousands of pages of oral histories of firefighters and emergency workers, as well as radio transmissions, were released. The Port Authority of New York and New Jersey, which owned the trade center and has its own police force, released all of its emergency recordings in 2003.
The Sept. 11 commission concluded in 2004 that the operators did not have enough information to allow more people to escape. Some took time to even know the towers had fallen.
"Are they still standing?" one dispatcher asked at 10:15 a.m., 16 minutes after the south tower collapsed. "The World Trade Center is there, right?"