Abstract: At approximately 11:00 a.m. on July 31, 2006, Employee #1, a Heating, Ventilation, and Air Conditioning technician, was performing condenser coil cleaning service on the air conditioning unit, Trane Number 12, one of thirty six units, situated on the roof of Ross Distribution Center located in Perris, California. While he was pressure washing the coils, he walked backward and tripped on a skylight, Tristar Skylights, Tri-Tuff/Tri- Arch Dome, Model Number 4896 SS-CM-H. Employee #1 fell through a 48 in. by 96 in. curb mounted skylight, approximately 43 ft to the concrete floor. He sustained serious injuries and was transported to Riverside County Regional Medical Center, then to Loma Linda University Hospital. Employee #1 was not protected from falling through the skylight.