Abstract: Employee #1 was working as a maintenance mechanic or maintenance engineer for a large department store. He was working from an aluminum ladder, attaching the leads of a voltmeter to the load side of a 480-volt disconnect switch to check for voltage. Although the system was energized, he was not wearing flame-resistant clothing, rubber insulating gloves, or suitable eye protection. An electrical fault occurred, and the ensuing electric arc knocked Employee #1 to the floor. Investigators found a screwdriver at the accident scene that they believed caused the fault. Employee #1 sustained second-degree burns to his right arm and first-degree burns to his face. He was hospitalized for 2 days for treatment of blisters and monitoring of vital signs. Normal skin color in the burned area of his arm was supposed to return in about 1 year.