Abstract: Employee #1 and coworker were changing a gasket in a steam line. Employee #1 entered a pit 3.5-ft by 10-ft deep using a ladder to loosen the bolts so that any water steam pressure could drain off. Employee #1 cut off the steam the day before on the boiler and locked onto when he thought it was drained. He returned to the pit to remove the bolts and replace the gasket. The coworker removed the ladder to allow work room and lowered a drop light. When Employee #1 removed the bolts, there was an explosion of steam and water. Employee #1 tried to climb out using the droplight until he received assistance. He received second and third degree burns to his chest, abdomen and legs. The trap on the bottom of the pit was found to be defective and there were no pressure gauges.