The lawyer for a New Jersey Transit train engineer that slammed into a station in September says his client suffered from an undiagnosed sleep disorder.

The crash into Hoboken terminal during the busy morning commute killed one woman and injured more than 100 others. Federal officials says the train accelerated unexpectedly just before the accident.

News sources report that Jack Arseneault, the lawyer for engineer Thomas Gallagher, said he sent sleep apnea test results for his client to the National Transportation Safety Board (NTSB) in late October.

Gallagher told officials he did not remember the crash, which is still under investigation by the NTSB.

With sleep apnea, breathing during sleep is disrupted, which can cause excessive drowsiness during the day. In adults, the most common cause of obstructive sleep apnea is excess weight and obesity. New Jersey Transit said the agency does have a sleep apnea screening program.

Senator Robert Menendez (D-NJ) said the accident illustrates the need for positive train control, a safety technology that can automatically stop or slow a speeding train.

A 2013 Metro-North crash that killed four people has been attributed to the engineer falling asleep because of undiagnosed sleep apnea.