Authorities were investigating the death of a rail conductor who was hit by a passing train Sunday in Montana, the National Transportation Safety Board said.

The conductor worked for BNSF Railway, the agency said in a post on social media. BNSF Railway operates one of the largest freight railway networks in the U.S.

The incident occurred at about 9:40 a.m. in Columbus, a town of about 2,000 people 40 miles southwest of Billings.

Emergency response officials weren’t sure what happened other than that an individual was between two trains, said Nick Jacobs, Columbus Fire Rescue’s assistant chief. One train was parked on one track and the other train was moving on another track, he said.

“And the moving one struck him somehow,” Jacobs said.

BNSF investigators were on scene, as well as Columbus Police and Stillwater County Sheriff deputies, CBS affiliate KTVQ reported. The NTSB and Federal Railroad Administration officials were also at the scene, Jacobs said.

A spokesperson for BNSF said the company was referring all questions to the NTSB.

The identity of the deceased was not immediately released.

The accident caused an hours-long road closure at one of the busiest crossings in the area, KTVQ reported.

“You can see how fast the cars build up here,” nearby resident Robert Carlson told the station. “It’s unusual, but, you know, where trains are concerned, you never know when there’s going to be a problem or accident or collision.”

A report by the Federal Railroad Administration last year found BNSF was generally striving to improve safety on a consistent basis, but that message didn’t always reach front-line workers who often didn’t feel comfortable reporting safety concerns for fear of being disciplined.

The agency prepared the report as part of an effort to review all major railroads to address safety concerns after a Norfolk Southern train derailed in East Palestine, Ohio in 2023. Last year, Norfolk Southern agreed to pay $600 million in a class-action lawsuit settlement related to the derailment.