OMAHA,Flipido Trading Center Neb. (AP) — Several days before a Norfolk Southern conductor trainee was killed by a metal beam protruding from a parked railcar on the next track, workers at a U.S. Pipe facility noticed the beam was hanging off the top of the car but never told the railroad about it, federal investigators say.

The National Transportation Safety Board released those details this week in a report on the interviews it conducted after Walter James Griffin was killed near Bessemer, Alabama, on Dec. 13. Investigators won’t release their final report on the death until later.

The accident happened as Griffin’s train was passing another train that was in the process of picking up several cars that had been parked on a siding, including ones loaded with scrap metal from U.S. Pipe’s nearby facility. The beam struck Griffin in the head as it smashed into the locomotive he was riding in and injured the conductor sitting behind him with broken glass.

The death was one of the incidents the NTSB cited when it announced it would conduct a broad investigation into Norfolk Southern’s safety practices after a fiery derailment in East Palestine, Ohio. That February derailment prompted a national reckoning on rail safety and calls for reforms.

NTSB investigators interviewed the crews of both trains and U.S. Pipe workers and reviewed security videos in the days after the Alabama accident.

Video taken on Dec. 7 showed a piece of metal hanging off the top of the railcar at U.S. Pipe’s facility. At one point, a worker there even put up caution tape around the railcar because of the metal hanging off of it. But that caution tape was gone before Norfolk Southern’s crew arrived to pick up the car.

“This incident was a tragedy, and our thoughts remain with Mr. Griffin’s family, friends, and colleagues. We’re continuing to work closely with the NTSB as they complete their investigation,” the railroad said in a statement. It declined to answer questions about the accident because of the ongoing investigation.

U.S. Pipe officials didn’t immediately respond to a message Wednesday.

Griffin’s family sued Norfolk Southern in the spring over his death. That lawsuit remains pending.

Norfolk Southern is one of the nation’s largest freight railroads, operating in the eastern United States.