Abstract: An electrician was working alone in a service vault. The electric equipment in the vault had been deenergized. The employee finished installing watt-hour meter bases in the 480-volt service panelboard. Before replacing the dead front panelboard cover, he reenergized the circuits, presumably to accommodate other trades at the jobsite. He was on about the third step of a stepladder in front of the panelboard when some small conductive object, perhaps a mounting screw from the top of the box, fell inside the upper portion of the panelboard. This caused an electrical fault, and the ensuing electric arc burned the electrician. He was hospitalized for his injuries.