Abstract: Employee #1 was a member of a crew that was using explosive charges to remove slag from the inside walls of a coal-fired steam boiler. The binary explosive charges consisted of ammonium nitrate and nitro methane. On each floor level, the boiler had a number of openings that were 6 inches wide, 8.5 inches high, and equipped with a door. To place an explosive charge in the boiler, one end of a 5-foot long broom stick would be attached to the end of a 24-foot long aluminum pole with duct tape. The explosive charge would then be attached to the end of the broom stick with duct tape. The blasting cap would be placed in the charge and the leading wires would be connected to the blasting cap. The leading wires would run from the blasting cap to a wire spool; from the wire spool, they would run to the blasting machine where the wires would be connected to detonate the charge. The pole setter, the person holding the aluminum pole, would then insert the end with the charge into the opening, and partially close the door. The pole setter would continue to hold the pole until the charge was detonated by the blaster, who was operating the blasting machine. The pole would then be withdrawn from the opening by the pole setter, and the process would be repeated. At the time of the accident, Employee #1 and another pole setter were working at the same time. They were each using a different boiler opening to insert charges. Another employee, the blaster, was connecting the ends of the leading wires to the blasting machine. The two spools that contained the leading wires from both charges were placed approximately 1.5 to 2 feet apart, and were close to the blasting machine. Employee #1 was placing a charge onto his pole, and was holding another charge. The charge that he was placing onto his pole already had the blasting cap in place, and was connected to the leading wires. The other pole setter had his charge already inserted into the opening of the boiler, and the blaster was planning to detonate that charge. However, the blaster inadvertently connected the wires of Employee #1's charge to the blasting machine, and after giving the warning of the impending explosion, detonated the Employee #1's charge by mistake. Employee #1 suffered extensive traumatic injuries and was killed.