Motorists who were trying to drive on 79th Street north of Highway 52 on Saturday, July 6, were in for a bit of a surprise. Detour signs were up. The problem was a sinkhole due to a failed culvert. As a safety precaution the hole was marked and the road was closed just north of the Niwot Loop Trailhead and recycling center. It was estimated that the culvert would be fixed and the road repaved by Tuesday afternoon or early evening, July 9.