Abstract: A power line worker was performing a switching operation. The employee was standing over an open underground vault located under a sidewalk. He was using a 2.4-meter-long live-line tool to close a switch on a 12-kilovolt backup circuit feeding three transformers. The switch was normally open; it was closed only to reroute power when the primary circuit was out. The normal anticipated load to be applied to the backup circuit was 15 amperes, and the 1-0 AWG cables for the backup circuit were rated at 25 kilovolts and 200 amperes. When the employee closed the switch, the cable failed. The ensuing electric arc burned the employee. He was hospitalized with first-degree burns to his face and arms and second-degree burns to the underside of his upper arms.