Story highlights The NTSB recovered train's data recorder Friday

Officials hope a second data recorder was working

(CNN) A data recorder that could have helped investigators answer why a New Jersey Transit train crashed in Hoboken last week was not working, the National Transportation Safety Board said Sunday.

"Unfortunately, the event recorder was not functioning during this trip," NTSB Vice Chairman Bella Dinh-Zarr said.

Investigators said the data recorder was over 20 years old.

The NTSB is looking for a second data recorder from a newer passenger car.

The recorder could provide information on the train's speed, use of brakes and throttle position.

Read More