Abstract: At approximately 9:50 a.m. on October 27, 1990, Employee #1 and a coworker were installing a new 10 ft by 12 ft by 8 ft acid dip tank in Department #1 of Davis Walker Wire, Hayward, CA. They were using steel alloy chain slings to position the tank into its permanent spot. The four chain slings were not marked with their weight capacity. Employee #1 had climbed onto the tank to release two of the safety chain slings when one of the slings bound up and would not release. Employee #1 was attempting to release the pin that held the hook onto the chain. When the pin released, chain sling #2 broke and the empty 11,500 lb tank dropped, causing Employee #1 to fall into the tank. He sustained serious injuries, for which he was hospitalized.