ANNAPOLIS, Md. (AP) - Police in Maryland investigating reports of a casket photographed bobbing up and down in a river discovered the object was something far less macabre. A post to a local radio station's Facebook page Tuesday showed a rectangular object with flat sides and a curved top floating in the South River, a tributary of the Chesapeake Bay near Annapolis. The concrete slab, resembling a coffin, sparked complaints of a possible hazard in the water, The Capital Gazette reported. Department of Natural Resources police were dispatched to the river, where a hydrographic operations team helped pull what turned out to be a floating dock from the water, according to the agency.