Abstract: Two employees of an electrical contractor were removing a 225-ampere circuit breaker from a 1600-ampere, 277/480-volt, Square D switchboard. The employees had not deenergized the switchboard before starting the job, nor were they wearing personal protective equipment. Employee #1 was performing the task, kneeling in front of the switchboard. Employee #2 was kneeling to his left. An electrical fault occurred, and the ensuing electric arc burned the two employees and ignited their clothing. Employee #l received burns to his chest, face, and arms. He died from his injuries. Employee #2 received burns to his right side, and he burned his hands from putting out the fire on himself and his coworker.