Gulf-to-Bay Boulevard is closed at U.S. 19 in Clearwater after officials said a truck hit the overpass.
According to the Florida Department of Transportation, the truck damaged a bridge girder when it hit the overpass.
Officials said the steel girder, which weighs about 70 tons and was part of the old bridge, is now hanging and needs to be removed.
Engineers will remove all four girders on the old U.S. 19 bridge over Gulf-to-Bay over the next 24 to 48 hours.
Motorists are advised to avoid the area and expect delays.
The detour includes westbound traffic heading north to Drew Street, using frontage road and then back to SR 60; eastbound traffic heading south to Belleair and then back to SR 60.
U.S. 19 is currently open in both directions.