EE WAS USING AN AIRLANCE THAT IS REINFORCED BY REBAR ON BOTH SIDES OF LANCE. HE WAS USING THIS LANCE TO POKE HOLES IN THE DIRT BUILDUP ON BOILER. AS HE WAS PERFORMING THIS TASK HE FELT A POPPI NG IN HIS BACK. MIDSECTION. THE AREA HE WAS WORKING ON WAS A LITTLE LOWER THAN HIS KNEES.