COLUMBIA, N.C. — North Carolina transportation officials say the Alligator River bridge on U.S. Highway 64 is closed until further notice because of a mechanical failure.

The N.C. Department of Transportation says in a news release Thursday the bridge is closed because of a failure in the swing span's locking mechanisms. A news release says work crews are on site to assess the problem and determine a timeline for repairs.

Officials are suggesting four detours to get around the closure.

NCDOT closed the bridge last March to replace the electrical and mechanical components to extend the life of the 58-year-old two-lane drawbridge over the Intracoastal Waterway and about 40 miles (64 kilometers) west of the Outer Banks.