PHILADELPHIA (AP) - Federal crash investigators say a backhoe operator had the right to be on the tracks periodically on the weekend an Amtrak train slammed into it, killing the operator and a supervisor.

PHILADELPHIA (AP) Federal crash investigators say a backhoe operator had the right to be on the tracks periodically on the weekend an Amtrak train slammed into it, killing the operator and a supervisor.

The National Transportation Safety Board released its latest report Monday on the April 3 crash south of Philadelphia. The southbound train was traveling 106 mph when it crashed into the backhoe.

The safety agency say the track where the backhoe was operating was shut down periodically during a 55-hour maintenance window. It's still unclear whether the track was closed to trains at the exact time of the crash. The NTSB says it's trying to determine "what roadway worker protections were in place."

The train was headed from New York to Savannah, Georgia, at the time.