WESTERLY, R.I. (AP) — The preliminary investigation into the death of an Amtrak conductor who fell from a train in Rhode Island last month found that the train was traveling about 40 mph at the time, the National Transportation Safety Board said Tuesday.

Based on surveillance video from a local business, investigators found that two of the train’s exterior doors were open with the stairs in the down position as the train arrived at the station in Westerly at about 2 p.m. on Jan. 15.

As the train was preparing to depart on its route to Washington, D.C., the assistant conductor radioed the conductor but did not receive a response, the report said.

The assistant conductor began searching the interior of the train and found an open door in a passenger car. The assistant conductor and the engineer then got out of the train and searched along the tracks. They found the conductor unresponsive about 1,200 feet east of the station platform, the report said.

The report did not include the conductor’s name. Local police previously said the conductor was a 26-year-old Massachusetts woman. She was pronounced dead at the scene.

NTSB investigators will now will focus on operating rules of the railroad, the mechanical condition of the train, and internal and external oversight of the Amtrak system, the report said.