Abstract: On June 7, 2010, Employees #1 through #4, of the City of Palmdale Dept. of Parks and Recreation, were provided pre-service training at Marie Kerr Aquatic Park. This pre-service training was to prepare the employees (lifeguards) to be assigned to work in the public swimming pools in the summer months. Employees #1 through #4 were instructed to perform exercises which included cherry pickers, lunges, bear crawls, and running, etc. These exercises caused the employees severe overexertion, dehydration, and painful swelling of the thighs and leg muscles. Employees #1, #2 and #3 were hospitalized for more than two days. Employee #4 was seen at the Kaiser clinic and released the same day. All four employees were diagnosed with Rhabdomyolsis and two with kidney failure.