Abstract: Employees #1 and #2 were shoveling muck at the bottom of a 31 foot gasoline tank compartment when they were overcome by gasoline vapors and had to be rescued. One worker lost consciousness and the other became semi-conscious. Both were hospitalized. Subsequent investigation revealed that no environmental checks of the tank -- LEL, oxygen, or PEL -- had been performed, no marine chemist had inspected the tank (as required), and no competent person performed checks. Employees were not trained in hazard communication regulations, and no respiratory protection was provided. One of the overcome workers who attempted to rescue his employee did not ensure that an adequate attended lifeline was available. An additional causal factor was that mechanical ventilation, supplied at the beginning of the operation, was turned off.