One man died and three others were injured in a blast at a fish processing plant in southern Mississippi on Monday, authorities said.
The explosion occurred in a large fish oil storage tank at a plant owned by Omega Protein Corp in Moss Point, on the Mississippi Gulf Coast, local fire chief Tommy Posey said.
The victims of the blast were subcontractors who had been welding and performing other maintenance work on some of the tanks, including the one that exploded, Posey said.
One of the injured men was in critical condition and undergoing surgery. The other two have been released from a local hospital, Posey said.
In addition to an investigation conducted by local authorities, the U.S. Occupational Safety and Health Administration was expected at the scene Tuesday morning to carry out its own probe, Posey said.
The plant, a major employer in the city with over 300 workers, has been cited by OSHA for problems in the past, Posey said.
In 2012, an Omega Protein worker died when he was caught in a rotating screw conveyor in an accident that federal investigators concluded was avoidable, local CBS and ABC affiliate WLOX-TV reported.
The plant will remain shuttered during the cleanup and investigations, Posey said.
Representatives for OSHA and Omega Protein did not immediately return messages seeking comment.