The incident commander at the scene of the deadly Metro-North crash praised the train's engineer Wednesday, saying he helped three or four passengers to safety before escaping the burning train car.

When the train struck an SUV Tuesday evening in Westchester County the third rail punctured the vehicle a few feet from the engineer's perch and pierced the floor of the first train car, starting a fire that killed five passengers, officials said. The SUV driver also was killed, and several other train passengers were injured.

"[The engineer] was right there in the front and his life was in danger, and he was able to get a couple people off, as well as passengers on the train assisted others," Valhalla Fire Chief Roger King said. They are "the heroes in something like this -- somebody who's risking their own life to get somebody else off the train, complete strangers."

Officials have not identified the engineer.

King said when the engineer briefed police and fire officials after the crash, he said he saw the car on the tracks and immediately locked up the brakes, "but they don't stop on a dime," King said.

"Instantly within seconds he had flames as well as smoke filling the train car," King said. "He was able to get the emergency windows popped to get people off the train."

King had just finished responding to a head-on crash on the Taconic State Parkway when he received a call over the radio about the Metro-North train crash.

By the time he got down Commerce Street, to the place where the train and the Mercedes SUV came to rest, the first car of the train was completely engulfed in flames, King recalled Wednesday.

"It was very chaotic," King said. "The hard part was the train tracks don't get plowed, so even though trains are able to go on them there's still a foot of snow, so everyone was self evacuating and had to stumble through a foot of snow," and first responders on the scene had to stumble through the snow to get to the fire and the victims.

King said because of the way traffic was diverted after the Taconic collision, speculation that the driver of the Mercedes was stopped on railroad tracks in heavy congestion was plausible.

"More than likely she just misjudged and she got stuck there," he said.

A safety gate hit the back of the SUV just before the vehicle was struck, federal officials said Wednesday.

Investigators are focusing on the potential for driver error, lighting at the crossing, the gate itself, and the third rail, among other factors, Sens. Charles Schumer (D-N.Y.) and Richard Blumenthal (D-Conn.) said in a conference call.

Schumer said the fact there may have been traffic at the crossing at the time "may have had something to do with this."

When King got to the scene, the fire was roaring and growing in intensity, he said.

A county police helicopter used infrared thermal imaging to search the hills and the snow for possible victims who might have wandered into the nearby cemetery, but found no one, King said.

With the snow a serious impediment, first responders used backboards as sleds to pull people away from the train through the snow.

Westchester Medical Center was notified of the accident at 6:44 p.m. Tuesday, Dr. Ivan Miller, medical director of the emergency department, said at a news conference at the hospital's Taylor Pavilion Wednesday afternoon. Three minutes later, the hospital went into Level 1 trauma center mode -- its highest level.

The emergency room and trauma center were quickly staffed with a team of doctors including four trauma surgeons, seven emergency medicine physicians, two orthopedic surgeons, one burn surgeon, one vascular surgeon, one pediatric surgeon, and at least three anesthesiologists. Ten operating rooms were prepared and fully equipped with physicians, surgical and nursing staff and anesthesiologists.

Miller described a scene involving teams of doctors wearing personal protective equipment over their white coats along with masks awaiting patients to be rolled into the trauma bays.

At 7:20 p.m., 12 patients arrived at the hospital, Miller said. Nine patients required trauma care, with five of them requiring Level 1 trauma care.

Vital signs were checked, their clothing cut, their bodies carefully rolled to the side "so we can look at every part of their body and make sure there are no missed injuries," Miller said.

Blood testsm and imaging tests including CAT scans were done to assess the damage, he said.

Dr. Joseph Turkowski, director of the burn center, said the hospital admitted a range of serious injuries including lacerations, contusions, crush injuries, open fractures, dislocations, smoke inhalation exposure and flame burn injuries.

As of about 2 p.m. Wednesday, one patient remained in critical condition, one patient in serious condition, four patients in fair condition, and two patients in good condition, according to Patricia Wrobbel, senior vice president of patient care services and chief nursing executive. Four patients had been discharged in the overnight hours.

Hospital officials would not go into any further detail regarding the injuries sustained or any ages of the victims, but said they were "hopeful" that all would survive.

The passengers who survived the crash but were injured were psychologically affected by the mass casualty incident that unfolded before their eyes, Miller said.

"One theme, in talking to several of the patients, even people with severe injuries, they were really focused on what they saw, what happened. What happened to other people on the train who were killed," Miller said. "So I'm sure these people will never forget what they saw. It's almost like a war-time experience where you see people die right in front of you.

"Even patients with fractures, lower-extremity fractures, described walking out," Miller said. "I guess the adrenaline rush kicks in and people can do things that they might not be able to do otherwise."

Chaplains and bereavement specialists were on hand to talk to the patients and their family members about coping with what had happened.

Wrobbel said the "quick actions" of the hospital staff mitigated any further seriousness of the patients that were injured.

"The silver lining here is the injuries and the extent of the injuries weren't as serious as they could be, comparatively to some other major trauma activations that we could have received," Turkowski said. "(It could have been) a lot more patients, a lot more serious injuries and it could have resulted in a lot more deaths so we are thankful for that."

Miller spoke of the sense of community felt at the hospital Tuesday night as the crash happened less than a six-minute drive away.

"Many of us take Metro-North and we have families that take Metro-North," Miller said, "so it does strike close to home."