Two workers are recovering from burns from an accident at a food plant in Norfolk. Norfolk Fire Capt. Lyle Lutt says firetrucks were sent to the Henningsen Foods plant around 1:20 p.m. Wednesday but found the initial propane fire extinguished. But as workers checked the propane system, propane spewed out of a pressure relieve valve and was ignited by a pilot light on a nearby machine. The new fire soon ignited gas coming from a pressure relief fitting on another machine.Two plant workers suffered second-degree burns on their faces, heads and arms. They were treated by firefighter medics but not hospitalized.