The Mathews Bridge will be completely closed to traffic for at least four days due to structural damage from a ship under tow hitting the span.
The ship that struck the bridge was the USNS Harry L. Martin, a Sealift Command vessel that was being moved from one part of the North Florida Shipyards to another.
A vertical ramp on the stern of the ship shows damage.
The U.S. Coast Guard said the ship was under tow. Crews are enforcing a 200-yard safety zone around the bridge while the accident is investigated.
The Florida Department of Transportation structural engineers were assessing the damage and structural integrity to the span.
"One of the supports was damaged," FDOT spokesman Michael Goldman said, adding the bridge is closed to ensure that the weight of vehicles does not cause additional damage.
Goldman said the bridge will remain closed to traffic at least through Monday.
"The damage to the concrete sections of the metal grating is extensive and the bridge will be closed for some time," said Rod Sullivan, a Florida Coastal School of Law professor who specializes in marine incidents.
The USNS 1st LT Harry L Martin Surge Sealift Ship belongs to Military Sealift Command. It is government owned and managed and operated by civilians. It is not a commissioned U.S. Navy warship or manned by U.S. sailors, but is a civilian-operated cargo ship owned by the Navy.
The Jacksonville Sheriff's Office is recommending the following detours around the Mathews Bridge: East/Westbound detours through the downtown area: Eastbound primary detour route is to the Hart Bridge via the Union Street Expressway to the sports complex exit. Westbound primary detour route is to the Hart Bridge via Cesery Boulevard to Atlantic Boulevard. Motorists should be aware of possible additional delays due to heavy construction.
Detours for Arlington, Fort Caroline and Regency areas: Interstate 95 north to Zoo Parkway to the Dames Point Bridge. Detours for Southside area: I-95 south to Emerson Street and University Boulevard exits.