Workers were scrapping a decommissioned oil rig in a shipyard along the Mobile River on Wednesday afternoon when the structure caught fire, sending heavy smoke billowing over the city, according to officials. Several fire trucks and boats responded to the rig, which contains diesel, hydraulic fluid, oil, and other potentially hazardous materials. No one was injured, but Mobile Fire-Rescue spokesperson Steven Millhouse said that officials are concerned about the "environmental effects" of the fire, which started just before 2:00 p.m. "Most of what we've got is residual mixed with water and the foam that we used to battle the flames, just kind of flowing off of the top of the rig," Millhouse told reporters at the scene.https://www.foxnews.com/us/alabama-oil-rig-catches-fire-mobile-river