i smell muslim terrorists, or is that Secaucus? (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. The train's engineer, identified as Thomas Gallagher, told NTSB investigators the train entered the Hoboken station at 10 mph. Witnesses have said the train was speeding as it entered the station instead of slowing down. Gallagher also told investigators he felt fully rested the day of the accident, and that his cell phone was stored and turned off, officials said. The investigation continues New Jersey Transit was under audit by the Federal Railroad Administration months before last week's deadly crash, a source with direct knowledge confirmed to CNN. The source said the audit was due to safety concerns. Some of the safety violations that sparked the FRA audit included "running through switches" and "yard operations," according to the source. Running through switches means the train would travel in a direction the switch on the train tracks weren't set for. Investigators looking into last week's crash have recreated the accident route and found no track signal issues. They have also documented the space using a drone -- a first for a rail accident, according to the NTSB. However, security videos, photos and 3-D models have so far provided no substantial insights. The investigation also involves a look at possible environmental factors that could have caused the crash. Thursday's accident happened during the height of morning rush hour, killing a woman waiting on the platform and injuring more than 100 others.