Jenny Doll had just arrived at her job as a store clerk early Wednesday when a thunderous explosion split the air and the building shook violently.

Doll, 30, and about a dozen other Costco (search) employees working near the warehouse store's loading dock rushed outside to find a splintered Metrolink (search) commuter train jutting into the parking lot.

Trapped passengers — some severely injured — screamed for help as flames raced toward the front of the mangled train car and smoke and diesel fumes filled the air.

The flames had almost reached at least six passengers trapped in the nose of the train car, said Doll, who with other employees attempted to douse the flames with small fire extinguishers.

Employees recounted a desperate scene, with forklift operators, truck drivers and stock clerks working side-by-side to pull victims from the wreckage before flames consumed them. They used store carts to wheel some of the most severely injured to safety.

"There were people stuck in the front. Everything was mangled," Doll said. "You could not even tell that it was a train cab at all."

Ten people were killed and 200 were injured just after 6 a.m. when a commuter train smashed into an SUV driven onto its tracks by a suicidal man.

The SUV driver, identified as Juan Manuel Alvarez (search), 26, of Compton, changed his mind about suicide and left the vehicle before it was hit, Police Chief Randy Adams said.

One elderly man from the back of the train was covered in blood and soot and appeared to have broken arms and legs. He was one of the last rescued before employees backed off because of leaking diesel.

"The man they took out of the back, he was mangled. I wish I never saw it," Doll said as she watched firefighters continue the rescue.

The elderly man survived for a few minutes after being pulled from the train, but died after thanking his rescuers, said Hugo Moran, a 34-year-old receiving clerk from Van Nuys.

"He was saying he was thankful [to be pulled out] because he didn't want to burn. He was saying, 'Pray for me, pray for me,"' Moran said. "I was telling him stay awake because he was going into shock."

Other said they were frustrated they couldn't do more with limited supplies.

"You can only do so much with small fire extinguishers. We really couldn't crawl in there," said Mark Zavala, a forklift operator. "A lot of people weren't able to get out."

Los Angeles Mayor James Hahn praised the Costco employees for their rescue efforts. After the initial rescue, store employees spent the morning providing survivors with water and clean clothes and cooking pizzas for firefighters. Most other nearby stores and restaurants had not opened.

"Personnel here at Costco rushed out with blankets and other supplies to help people," Hahn said. "There were a lot of good stories in that respect."

Dennis Davenport, assistant store manager, said he was proud of his employees.

"I think they were pretty shaken up. I'm just glad none of them were hurt," he said, adding that the employees didn't have specialized first aid training.

Other Costco workers rushed to the scene only to be forced back by thick smoke and diesel fumes. Many were afraid the wreckage would explode, they said.

Hernan Tobar said he and several employees wanted to help, but were pushed back by the smoke.

"Some people came out bleeding from the forehead, limping. Everybody had something different — their own injuries," said Tobar, a 23-year-old stock clerk. "Some people, I'm amazed, came out unhurt."