Abstract: Employee #1 was the night shift supervisor at a warehouse. A driver, an owner/operator working for Employee #1's employer, was reporting to work with a company trailer equipped with a rear hydraulic lifting device chained in the raised position. To dock the trailer, the safety chains were normally released at the dock by an employee working in the warehouse loading bakery products. The loader working in #1 dock bay attempted to release the safety chains but could not reach them. Employee #1, his supervisor, told the driver to move the rig away from the dock, then walked out the access door and went downstairs and behind the trailer. As he was attempting to release the safety chains, the trailer moved backward, crushing him against the raised dockplate. The driver was unable to see Employee #1 and was unaware that he had left the loading dock area. Company work practice did not provide for the removal of the safety chains by the truck drivers prior to docking, although it was common practice for loaders to release them after the trailer was docked.