A fire at the Westlake Vinyls chemical plant on La. 73 in Geismar has been extinguished following an explosion early Thursday in the vinyl chloride monomer facility, authorities and plant officials said.

A shelter-in-place order is in effect for residents within a one-mile radius of the facility, State Police and Ascension Parish Office of Homeland Security and Emergency Preparedness said.

No word yet on possible injuries.

State Police, the Gonzales Fire Department, Geismar Fire Department and Ascension Parish Hazardous Materials team are on scene.