Recently an incident occurred involving an unsecured lid of a cargo box. The crewmembers opened the cargo box to begin unloading supplies. There was no locking bar on this box, only a welded chain, which allowed the box to be opened to a position that it would not fall closed. One of the chain loops twisted and rolled under the welded loop. This took out some of the chain slack that was needed to allow the lid to be opened to the safe position. This allowed the box lid to fall, striking the employee on top of his hands. The injured employee sustained a minor injury.