Abstract: At approximately 7:30 a.m. on December 11, 2008, Employee #1, a journeyman electrician with First Electric Services, was replacing a 125-amp circuit breaker on a 600 amp, 440 volt electrical panel. Before being sent to the job site, he was reminded by a supervisor to shut off the main power before beginning work. A coworker reminded Employee #1 as the coworker dropped him at the job site. The coworker left Employee #1 to work alone while he proceeded to retrieve a new breaker for the panel. As Employee #1 was placing a screw back into its respective hole, it fell and his screwdriver made contact with two separate phases, resulting in a phase-to-phase fault and an arc flash. The coworker arrived back on the job site just after the accident and summoned emergency responders. Employee #1 was hospitalized at USC Medical Center for second-degree burns to his face, the back of his right hand and thumb, and his index, middle and ring fingers. Employee #1 admitted he knew he should have shut off the main power switch prior to beginning work on the electrical panel but was probably preoccupied with a sick relative in another country.