Is it ensure, insure, or assure?
1804, in reference to those who salvage cargos from wrecked ships, from wreck (n.). In Britain often with a overtones of "one who causes a shipwreck in order to plunder it" (1820); but in 19c. Bahamas and the Florida Keys it could be a legal occupation. Applied to those who wreck and plunder institutions from 1882. Meaning "demolition worker" attested by 1958. As a type of ship employed in salvage operations, from 1789. As a railway vehicle with a crane or hoist, from 1904.