Federal investigators probing a deadly crash involving a New York commuter train and a SUV have focused on the behavior of the vehicle's driver, who was identified Wednesday as a 49-year-old mother of three. 

Five men on the train, as well as the SUV's driver, were killed late Tuesday in the deadliest accident in the 32-year history of the Metro-North commuter rail. The train smashed into the Mercedes ML350 driven by jewelry store employee Ellen Brody, which had become stuck on the tracks between the railroad crossing gates. 

"The big question everyone wants to know is: Why was this vehicle in the crossing?" said Robert Sumwalt, National Transportation Safety Board vice chairman.

The wreck happened after dark in backed-up traffic in an area where the tracks are straight but driving can be tricky. Motorists exiting or entering the adjacent Taconic State Parkway have to turn and cross the tracks near a wooded area and a cemetery.

Witnesses said Brody calmly got out of her vehicle after the crossing gates came down around her and hit her car. She then got back in and drove forward before the train hit the car, killing her instantly. 

"It looks like where she stopped she did not want to go on the tracks but the proximity of the gate to her car, you know, it was dark -- maybe she didn't know she was in front of the gate," Rick Hope, who was in the car behind Brody, told WNYW.

"I said to myself, 'The clock is ticking here, the gate is down, the bells are ringing — what are you going to do here?'" Hope added. "She looked a little confused, gets back in the car and pulls forward on the tracks."

Traffic was moving slowly at the time, choked with drivers seeking to avoid the Taconic State Parkway because of an accident, Hope noted.

As of Wednesday evening, investigators had no evidence the crossing gates weren't working properly, but their examination was just beginning, Sumwalt said.

Among other things, investigators also planned to examine the tracks, interview the crew and find out whether the SUV had a data recorder of its own.

Railroad grade crossings typically have gate arms designed to lift automatically if they hit a car or other object on the way down, railroad safety consultant Grady Cothen said. The wooden arms are designed to be easily broken if a car trapped between them moves forward or backward, he said.

Acknowledging that collisions between trains and cars rarely cause rider deaths, Sumwalt said the NTSB would also examine the adequacy of the train's exits and the intensity of the fire, which investigators believe was sparked by the SUV's gas tank.

Sen. Charles Schumer, D-N.Y., said early indications are that the train was going 58 mph, or within the 60-to-70-mph speed limit in that area. The NTSB said it wanted to confirm speed and other data extracted from the recorder before releasing it.

It was not the first deadly crash at the site: A Metro-North train hit a truck, killing its driver, at the same Commerce Street crossing in 1984, according to Federal Railroad Administration records.

Rep. Patrick Maloney, D-N.Y., said Tuesday's accident underscores the need for positive train control, a technology that uses WiFi and GPS to monitor trains' exact position and automatically applies the brakes to prevent collisions or lessen their severity. While not specifically designed to address grade-crossing accidents, the technology can be expanded for such purposes, he said.

Congress passed a 2008 law that requires all railroads to install positive train control by the end of 2015, but it's clear most of them will not meet the deadline.

The crash was so powerful that the electrified third rail came up and pierced the train and the SUV, and the SUV was pushed about 1,000 feet, Sumwalt said. The blaze consumed the SUV and the train's first car.

Elizabeth Bordiga was commuting home from her New York City nursing job when she suddenly felt the train jerk a few times. She and other passengers in the middle part of the train started calmly walking to the back. But then they started smelling gasoline, and somebody said there was a fire.

But they couldn't open the emergency window or figure out how to escape until a firefighter got a door open, she said. Commuters lifted each other down from the train to the ground about 7 feet below, said Bordiga, who uses a cane.

"When I was on the ground, I looked to the right and saw flames," she said. "I couldn't believe it."

The train's engineer tried to rescue people until the smoke and flames got so severe that he had to escape, Westchester County Executive Rob Astorino said

While officials did not immediately release any victims' names, employers confirmed that the dead included Walter Liedtke, a curator of European paintings at the Metropolitan Museum of Art, and Eric Vandercar, 53, a senior managing director at Mesirow Financial.

Every day, trains travel across more than 212,000 highway-grade rail crossings in the U.S. There are an average of 230 to 250 deaths a year at such crossings, down over 50 percent from two decades ago, FRA figures show.

Risky driver behavior or poor judgment accounts for 94 percent of grade crossing accidents, according to a 2004 government report.

Metro-North is the nation's second-busiest commuter railroad, after the Long Island Rail Road, serving about 280,000 riders a day.

Late last year, the NTSB issued rulings on five Metro-North accidents in New York and Connecticut in 2013 and 2014, repeatedly finding fault with the railroad.

Among the accidents was a 2013 derailment in the Bronx that killed four people, the railroad's first passenger fatalities, The NTSB said the engineer had fallen asleep at the controls because of a severe, undiagnosed case of sleep apnea.

The Associated Press contributed to this report.

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