Train 'folded like an accordion'

A rescue worker transports a victim to a waiting ambulance at the site of the train collision Tuesday.

ANAHEIM, California (CNN) -- Cindy Castaneda was riding in the second car of a Metrolink commuter train Tuesday morning, coffee in hand, when the train slammed on its brakes. Coffee went flying -- Castaneda, too.

"I thought that was so weird," she said. "It was just this tremendous bang that I have never, ever heard before, and we all went flying."

The small commuter train, packed with about 300 people, and a mile-long freight train collided head-on in Placentia in southern California. Two people were killed and 162 others were either treated at the scene or transported to several hospitals in the area.

The impact crumpled the commuter train's first car, knocking it partially off of the tracks.

Many people on board the train at first did not realize what had happened.

CNN NewsPass VIDEO CNN's Anne McDermott reports investigators are still trying to figure out what happened in the train collision the left two dead and dozens injured (April 23) Play video A commuter train and a freight train collided in Placentia, southern California, on Tuesday morning. (April 23) Play video   MORE STORIES 2 dead, dozens injured in California train collision    Metrolink Information • If you are concerned about family who may have been on the train call: 1-800-371-5465     EXTRA INFORMATION Gallery: Images from the California train collision  Map: Commuter train route

"I heard somebody say we hit something, but we didn't feel the impact for another couple of seconds," passenger Alex Cuevas said. "I flew out of my seat and hit something up front, as the roof collapsed."

"I remember the train was slowing down, which it normally does at a crossing," said a female passenger who was riding in the front car. She felt a "really hard jerk" and the ceiling started buckling, she said. "It folded like an accordion. People were flying out of their seats."

"I was reading the newspaper and I had my legs crossed," a male passenger said. "Everything was in slow motion, my nose hit front chair. I was rolling all over the place -- all I could hear was everyone screaming."

After the crash, passengers exited the train, going through windows and doors that were not damaged.

"I was in the first car and we made sure that everyone was OK and then we all tried to get out. The back was blocked because it was crumpled," a male passenger said. "In the front, there were people all in the stairwells, we had to clear those people -- we didn't move them, we made sure that they were okay and then we cleared a path."

Police officials said the Orange County Fire Authority was mobilizing for an emergency training exercise at the time of the crash, allowing rescue workers to respond quickly. Emergency crews set up a makeshift triage center was set up in the gravel next to the tracks to treat the dozens of victims.

The National Transportation Safety Board is investigating why the trains were on the same track.