A fire at a national lab in South Carolina that is on a site that once made key parts for nuclear bombs triggered an emergency response that shut down incoming traffic and restricted air and rail service in the area. The fire broke out Wednesday at the Savannah River National Laboratory on the U.S. Department of Energy’s Savannah River Site. The emergency was declared at 5:39 p.m., and the fire was then extinguished. A Savannah River Site statement says no contamination was reported outside the affected facility. The Savannah River Site is a massive complex where the federal government once produced materials used in nuclear weapons, primarily tritium and plutonium-239.