Abstract: At approximately 7:10 a.m. on February 2, 2010, Employee #1 and Employee #2, refrigeration technicians of Hill Phoenix, were servicing a supermarket's A/C and refrigeration systems. Employee #2 went downstairs to get some tools. Employee #1 closed the valves of compressor #1 and the valves at the oil separator. He also discharged compressors #2 and #3. However, compressor #4 got charged, there was a sudden pressure (energy) buildup in the refrigerant line. It ruptured the 2.125 in. copper inlet line of the oil separator. The line swung around and damaged other copper lines. Employee #1, who was standing nearby the damaged copper line(s) was struck by flying debris. He was transported to the hospital for treatment of a broken leg and a minor facial injury.