Nearly three weeks since Baltimore’s Francis Scott Key Bridge collapsed under the impact of a wayward cargo ship, crews are using the largest crane on the Eastern Seaboard to haul the wreckage to a nearby salvage yard. The heaviest section so far weighed about 450 tons (408 metric tons). In the salvage yard Monday morning, workers disassembled the metal trusses by attacking them with propane torches and a pair of giant shears that sliced them into more manageable pieces.