A blaze broke out about 4 a.m. Friday morning at the ExxonMobil refinery in Baton Rouge, but a company spokesperson said it was fully extinguished by 6:45 a.m. and there were no injuries.

Baton Rouge firefighters were on hand to monitor the area outside the plant, but the fire did not spread beyond the factory, said Curt Monte, a spokesman for the fire department.

Stephanie Cargile, an ExxonMobil spokesperson, said the “loud boom” neighbors might have heard was a “noise that was related to the de-pressuring of the unit, which is part of the procedure to quickly and safely purge hydrocarbons from the unit.”

She said an investigation is underway to determine the cause of the blaze.