The NTSB is on the scene in Brooklyn looking into Wednesday's Long Island Rail Road crash. More than 100 were injured, but no one was killed. NY1's Jose Martinez filed the following report.

Federal investigators arrived in Brooklyn Wednesday night to begin piecing together what led to the morning crash at the Atlantic Terminal.

"Track. Operations. How the trains are run, the ules. Mechanical, which includes the power, mode of power and equipment. Signal systems. Human performance," said Jim Southworth of the National Transportation Safety Board. 

In short, everything connected to the crash in which Long Island Rail Road train 2817 plowed through a barrier and left at least 104 injured as the first car derailed.

The train was arriving from Far Rockaway, Queens at aroud 8:20 a.m., carrying more than 400 commuters. 

"Our mission is to understand not just what happened, but why it happened," Southworth said.

NTSB officials sounded a similar refrain after a New Jersey Transit train plowed into a platform at the Hoboken Terminal in September, killing a woman. But Southworth, who was an investigator in that case, cautioned against tying the crashes together too closely.

"My main concern while I'm on site here is to investigate this accident in this terminal from beginning to end without concern related to what was going on Hoboken," he said.

Officials said the train was in a 5 mph zone when it crashed. Robert Paaswell, a City College engineering professor who once headed the Chicago Transit Authority, said a lot is in the train operator's hands at that point.

"Once it's in the station, going less than 10 or 15 miles an hour, the engineer is in control. So the engineer has a routine and standard operating procedures. They know what steps they should do," Paaswell said.

Investigators said they expect to begin talking with the three-person crew on Thursday and to examine the contents of the train's recorders.

Mark Epstein, the head of the Long Island Rail Road Commuter Council, said the latest LIRR crash, which follows another in New Hyde Park in October, is troubling.

"We pay exorbitant fares, and the only request is on-time performance and safe performance. So we as a council will continue to push for more and more safety," Epstein said.

NTSB officials say they expect to remain on the scene in Brooklyn for up to a week as they embark on the initial stages of their investigation.