Abstract: At approximately 9:40 a.m. on March 9, 2000, Employee #1 of San Diego Chiller Service, Inc. in San Diego, CA suffered a serious electrical flash burn injury while performing maintenance work on a condenser pump starter panel. To access this panel, he unlocked the cabinet and moved the circuit breaker to the "off" position. After checking the panel to ensure that it was not hot, he proceeded to perform the necessary maintenance tasks, including reinstalling a missing relay. Unknown to Employee #1 and to any other persons with knowledge of the panel, the 250 amp bus wires were directly behind the location of the relay mounting screw holes. As Employee #1 drove the mounting screws into the holes, the screw penetrated the insulation and came in contact with the hot bus wire. An electrical arc and flash immediately started a fire in the back of the panel, and burned Employee #1's left arm. Employee #1 was taken to UCSD Medical Center for treatment and surgery.