Abstract: At approximately 1:00 p.m. on August 31, 2006, Employee #1 was conducting electrical preventive maintenance and testing on Switchboard RM-3 at the San Diego County Water Authority's Olivenhain Pumping Statio. RM-3 was a three-phase, four wire metering station of 277/480 volts and 1,600 apms. He was using a ductor testing device on the switchboard while cleaning the insulators around the busbar. Employee #1 had moved the clamp on the ductor tester equipment from the Phase A bus to the Phase B bus when the breaker flashed, causing an explosion. He suffered second- and third-degree burns to his left forearm and palm, as well as lesser burns to his face and ear. Employee #1's supervisor was walking to the pumping station when the explosion occurred, and he called 911. Employee #1 was transported by ambulanced from the dam to meet a medical helicopter. He was then airlifted to the UC-San Diego Burn Center. As of September 5, 2006, Employee #1 remained hospitalized. He expected to be released soon, but did not know when he would be able to return to work.