The National Transportation Safety Board has determined the garbage truck struck by an Amtrak train carrying Republican lawmakers to a retreat in West Virginia last month was in the railroad crossing at the time of the crash even though safety gates were lowered.

The agency, which is investigating last month’s incident near Crozet, Va., released a preliminary report Wednesday on the collision. According to the report, a track image camera fixed to the train’s lead locomotive showed that as the railroad crossing came into view, the truck was in the crossing, but the gates were down.

Witnesses also told the NTSB the truck entered the crossing after the gates had lowered.

The Amtrak train was traveling at about 61 miles per hour when its engineer started braking. The train then hit the garbage truck, which spun and crashed into a railroad signal bungalow located next to the tracks.

The NTSB found that the truck’s two passengers were ejected from the vehicle. One of the passengers died, while the second sustained serious injuries. The driver, 30, had minor injuries.

Three Amtrak employees and three passengers on the train also sustained minor injuries.