Firefighters from Copiah County and surrounding areas responded to a fire Friday at a chemical plant.The fire broke out in one of the towers at Westlake Chemical off Highway 51 in Gallman. Copiah County EMA Director Randle Drane said the tower contains mineral oil, but no hazardous chemicals. The building was evacuated and no injuries were reported, Drane said.Fire crews from Copiah and Hinds County and volunteer firefighters from Byram, Terry, Utica, Raymond and Pocahontas responded. Officials with the Mississippi Department of Environmental Quality were also at the scene, Drane said.The cause of the fire is under investigation.