HOBOKEN -- Efforts to recover a functioning event-data recorder from the New Jersey Transit train that crashed into Hoboken Terminal last week are expected to continue Monday after investigators disclosed that the first recorder wasn't working.

The event recorder removed from the locomotive of the NJ Transit train that crashed Thursday in Hoboken.

A newer recorder that might provide clues to the cause of the crash that killed one woman and left more than 100 hurt is buried under a collapsed section of the station's roof, according to T. Bella Dinh-Zarr, National Transportation Safety Board vice chair.

She said the recorder in the front of the train that remains inaccessible is from the 2000s. The recovered recorder, which was later deemed inoperable after being sent to the manufacturer, was from 1995.

"That's quite an old data recorder," Dinh-Zarr said. "It's likely that it's a newer event-data recorder in the lead passenger car, the controlling car, so we're hopeful that will have information that will be functioning."

Among other information, the data recorder could provide crucial information regarding the speed of the train prior to the crash.

The train is only required to have a working event-data recorder in the lead car, investigator-in-charge Jim Southworth told reporters.

Dinh-Zarr said NTSB investigators used a drone for the first time to take photos of the accident. They also used a laser-scanner to create 3-D images of several of the cars, she said.

Dinh-Zarr said the train's engineer told investigators that the train was operating properly before it crashed Thursday morning. The engineer has no memory of the crash itself and didn't know the cause, Dinh-Zarr said.

Asked if it was possible the train was going only 10 mph into the station and whether there was any indication the engineer was applying the brakes, Dinh-Zarr said the NTSB would not know until they get that information from the recorder.

"We don't want to give an answer that is not perfectly accurate," Dinh-Zarr said.

Dinh-Zarr was asked to shed light about the dozens of NJ Transit violations discovered by the Federal Railroad Administration this summer.

She said the NTSB is conducting the crash investigation independently from the FRA, but that the FRA audit "will definitely be part of our process."

LOOKING AT VIDEO

The NTSB will also be reviewing "a lot of different types of" other video recordings, including videos from other nearby trains, and speed could also be determined from those videos, if necessary, Dinh-Zarr said.

The tracks were not equipped with an automatic system called Positive Train Control, which could have controlled the speed of the train.

After it was apparent that NJ Transit and other railroads would miss the original Dec. 31, 2015, deadline for installing PTC, Congress voted to extend the timetable by three years.

Asked about whether PTC could have prevented this crash, Dinh-Zarr said it has been a priority for the NTSB and is known to prevent many types of train accidents.

"But what we need to remember is PTC cannot prevent every train accident," Dinh-Zarr said. "We will look to see if it affected this one. We just don't have enough information yet."

Overlapping debris from the crash hindered the investigation by preventing safety-board investigators from reaching all of the train cars, Dinh-Zarr said.

Marisa Iati may be reached at miati@njadvancemedia.com. Follow her on Twitter @Marisa_Iati. Find NJ.com on Facebook.