Federal investigators say it might take some time to figure out what caused Thursday's deadly train crash in Hoboken.

The National Transportation Safety Board says it may be another two days before there is full access to the crash site. 

The New Jersey Transit train barreled into the platform of the Hoboken Terminal station just before 9 a.m. Thursday. 

Fabiola Bittar de Kroon, 34, was standing on the platform when she was struck and killed by falling debris. 

More than 100 other people were hurt in the crash, most of them with minor injuries. Many have been treated and released from nearby hospitals.

The NTSB says it's examining a range of factors, from the train's speed and braking ability to the engineer's health at the time of the crash.  

"Our objective as always is not just to find out what happened, but why it happened, so we can prevent it from happening again," said Bella Dinh-Zarr, vice chairman of the NTSB. "Let me reiterate that this is the fact-gathering phase of the examination, so we will not be determining the probable cause on scene, nor will we speculate about what may have caused this accident." 

Investigators say the train's engineer, Thomas Gallagher, is cooperating. He has worked for New Jersey Transit for 29 years and has been an engineer for 18.