Photos released by the U.S. Navy show the wreckage of the Francis Scott Key Bridge resting at the bottom of the Patapsco River in Baltimore, Maryland. The U.S. Army Corps of Engineers posted the 3D images online Tuesday. They were supplied by the Navy's Naval Sea Systems Command (NAVSEA) Supervisor of Salvage and Diving (SUPSALV) and were taken by divers with an underwater sonar imaging tool, called the CODA Octopus. "These 3D images show the sheer magnitude of the very difficult and challenging salvage operation ahead," the Army Corps of Engineers said.Murky water and mud at the bottom of the river limited