CHICAGO — A portion of Lake Shore Drive will remain closed after crews declared a "structural emergency" on a bridge Monday.
Just after 11:30 a.m., the Chicago Department of Transportation shut down the northbound lanes at Monroe Street to Grand Avenue. A CDOT crew working in the area discovered a cracked steel beam supporting Lake Shore Drive near Randolph Street leaving the roadway uneven.
While they were starting repairs, they inspected the rest of beams and found another one with a crack on the other side. In response, the ramp from eastbound Wacker Drive to the southbound Lake Shore Drive was closed.
CDOT said the wild temperature swings in the last couple of weeks likely played a role in the metal fatigue that caused the two steel beams to fail.
That is two girders that failed out of seven on the stretch of viaduct.
CDOT crews are working to install a shoring tower under the viaduct to support the structure.
Officials said they hope to reopen that section by Tuesday night. But that will only be a temporary fix. Permanent repairs will take weeks.
No injuries or vehicle damages were reported.