GIBSON - Authorities said three people died and two others were seriously injured in an explosion at a natural gas plant in Terrebonne Parish Thursday.

A representative for the Williams Field Services confirmed the deaths during a press conference Thursday afternoon in Gibson. The plant said contract workers were doing maintenance around 11 a.m. when the explosion happened.

One worker was burned badly enough that they were taken to the Baton Rouge General Burn Unit.

Williams Partners released a statement saying 13 Williams employees working at the facility at the time are accounted for and not injured. The company said the facility was not operational and gas was not flowing through the pipeline system when the explosion happened.

"We are deeply saddened by reports of serious injuries to personnel working at the scene. Our thoughts and prayers are with them and their families at this very critical time," said Warren Toups, Williams Operations Manager.

People living in the 4700 block of Bayou Black Drive were told to evacuate or stay inside of their homes, according to the Terrebonne Sheriff's Office.

Louisiana State Police said federal investigators are on their way to the plant to find out just what caused the explosion.