AIKEN, S.C. (AP) — A fire Wednesday 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 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.

No contamination was reported outside the affected facility, according to a Savannah River Site statement.

Employees in areas impacted by the fire and not involved in the response were also sheltered, according to the statement.

The Savannah River Site is a massive complex where the federal government once produced materials used in nuclear weapons, primarily tritium and plutonium-239. The lab is in its northwest corner.

The site was opened in the early 1950s to manufacture the plutonium pits needed to make the core of nuclear bombs during the start of the Cold War with the Soviet Union.

Today it is used for environmental stewardship and cleanup, along with nuclear waste management and disposition of nuclear materials, according to the U.S. Department of Energy.