The New York Fire Department has released audiotapes of the final radio communications of firefighters in one of the towers of the World Trade Center shortly before they collapsed.

Seventy-eight (floor) seems to have taken the brunt of the stuff. There's a lot of bodies. They said the stairway is clear all the way up, though

Recording of Scott, firefighter

They are thought to be the only recordings of rescuers as they tried to reach the dead and injured on the upper floors of the buildings.

The tapes remained sealed off from the public for more than a year but were released following a court request by the New York Times newspaper.

The firefighters can be heard speaking over their radios, unaware of the trouble they were in.

Their voices are calm as they receive instructions and report back what they see before them in the stair wells of the South Tower.

"I just got a report from the director of Morgan Stanley," a firefighter named Scott on the 48th floor said.

"Seventy-eight (floor) seems to have taken the brunt of the stuff. There's a lot of bodies. They said the stairway is clear all the way up, though."

Third plane

Among the transmissions a firefighter is heard setting up a staging area for wounded people on the 40th floor. Others are heard trying to make their way up the stairs.

Soon after the planes hit the towers, there are warnings of a third plane on its way.

"We got reports of another incoming plane," says a firefighter. "You may have to take cover. Stay in the stairwell."

Seconds later, it becomes clear the aircraft is not part of the terrorist attack.

For some of the victims' relatives the tapes will mean a great deal, knowing their loved ones were comforted by firefighters in the final moments before the tower collapsed.

For fire chiefs who have been criticised for failures in radio equipment that day, the radio transmissions are evidence that firefighters were able to communicate in one of the towers.