SABULA, Iowa (AP) — Safety concerns have forced the closure of a small bridge that offers the only Iowa access to a much-larger bridge spanning the Mississippi River and connecting eastern Iowa to western Illinois. Motorists commuting from Sabula to Savanna, Illinois, or vice versa, are facing a 36-mile detour after the unexpected bridge closure Tuesday. Iowa Transportation Department Planner Sam Shea tells the Telegraph Herald that the bridge could be closed until May and reopened around Memorial Day.

The closure comes after state officials found portions of pavement on the Sabula bridge to be settling Monday. A more thorough inspection Tuesday found more issues. Officials already had been planning to replace the bridge, which was built in 1933. Shea says it’s unclear how the early closure will affect bridge replacement costs.