MIAMI—The Miami-Dade County Courthouse will begin undergoing repairs immediately because of safety concerns found during a review prompted by the deadly collapse of a nearby condominium building, officials said. An engineering firm that examined the 28-story courthouse recommended that it undergo immediate structural repairs and that floors 16 and above be closed. All courthouse employees, including those who work on lower floors, will return to working from home, Miami-Dade Mayor Daniella Levine Cava and other leaders said in a joint statement late Friday. In its report, engineering firm U.S. Structures Inc. said that during its June 30 inspection, it found structural distress in various structural members such as support beams and joists, including steel columns that are in “poor condition” and concrete columns that have numerous cracks. “In general, we observed numerous members with visible signs of structural deterioration that have been documented and reported by this and other firms …