Nucor-Yamato Steel in Blytheville, Arkansas suspended operations after a locomotive operator at the plant died in an accident at the mill.
Authorities say 54-year-old Bobby Sellars of Burdette died after being pinned between two rail cars Tuesday afternoon.
In a statement, Nucor-Yamato vice president and General Manager Leon Topalian said the company will work with federal investigators to determine the cause of the accident.
Topalian said Sellars had worked for the steel mill for 27 years.