The Plymouth Avenue Bridge in Minneapolis is likely to remain closed all winter, city officials announced Thursday.

The city has retained a Florida engineering firm to continue to investigate the cause and extent of cable corrosion that prompted the sudden closing a week ago, and to design solutions for the problem, City Engineer Steve Kotke said.

Kotke said doing further checks of the bridge and implementing corrective measures likely would be complicated by occupational safety requirements for such work in the winter.

The 1983 bridge daily carried about 10,000 vehicles, which are now detoured to the nearby Broadway or Hennepin Avenue bridges. The city adjusted traffic signal timing at the Broadway-NE. Marshall Street intersection to reduce backups on the Broadway bridge.

Kotke he's willing to consider whether the Plymouth bridge could reopen to pedestrians and bicyclists after the consultant has completed a preliminary analysis.

Dozens of cables inside the bridge's box girders are tensioned to squeeze sections of the bridge into a whole. Kotke said that continuing daily checks by a survey crew have found no signs that the bridge sections are shifting. The bridge is designed so that failure of a single part does not cause collapse.