Screams of anguish reverberated across the phone line — the only clue dispatchers needed to gauge the magnitude of the tragedy.

A train crash. Bloody victims. Desperate callers pleading for help.

"We have a whole bunch of people now bleeding and on the floor," one man told a 911 dispatcher in a trembling voice.

Click here to see a video report about the release of the 911 calls.

The man was among hundreds of callers who described a chaotic scene following the collision Sept. 12 between a Metrolink commuter train and a Union Pacific freight engine. The wreck killed 25 people and injured more than 130 others.

Fire officials released a few recordings of the calls Wednesday night following several media requests.

Some callers seemed calm, others frantic.

"Please hurry!" one person urged the dispatcher. "People are bleeding and hurt here."

One man told the dispatcher he wasn't sure what the train hit. Together, amid the chaos, the injured passengers slowly discovered what happened.

Click to view photos | Click for more at MyFOXLA.com.

"I can see about seven or eight people, in the one car I'm in, that are bleeding or on the floor," a passenger told the dispatcher.

As survivors emerged from the wreckage, they saw the first passenger car that had crumpled under the force of the Metrolink engine.

"I bet you're going to have a lot of fatalities there," one caller said.

As the fire in the freight train intensified, passengers scrambled to move away.

"There's a possible explosion from the freight train," a man told the dispatcher. "There's a lot of people who are down. Just looking at that car, it looks real bad."

Another dispatcher warned a rescuer to stay away from the twisted metal and flammable fuel.

"If you see people jumping out or moving out of that vehicle, you can assist them to get them out of any danger," the dispatcher said.

The calls released were a small sample of the hundreds that dispatchers received in the hours after the collision, fire spokesman Ron Myers said. The city only released a few because it would take hundreds of hours to assemble and distribute all of them, he said.

Click here to read the story of one crash survivor in OnTheScene.