Abstract: At approximately 9:00 a.m. on July 24, 2011, Employee #1 was working on the roof of a commercial building in Azusa, CA, to remove and replace skylights. As he was working, he fell through a skylight opening. He fell approximately 16 feet, landing on the metal grate floor of the mezzanine below. He was transported to Los Angeles County and USC Medical Center, where he was treated for a left scapula fracture, a left humeral head fracture, and a left transverse process fracture. He remained hospitalized for more than two days. The employer, Douglass Colony Group Inc., had been contracted to reroof a warehouse building including the removal and replacement of 125 skylights. The employer sent out 12 employees, including two foremen (one crew per foreman). The employer provided safety equipment and supplies (including two fall protection carts, 11 roofers fall protection kits, one 60-foot horizontal lifeline, four cross arm anchors, and two generators), which were available and ready for use on the day of the accident. The safety equipment and supplies were on site for employees to use while working around the skylights, but they were not used. On the day of the accident, Employee #1 was kneeling down and helping to install roofing membrane across an open skylight. The opening measured approximately 4 feet by 8 feet. Employee #1 was working with the foreman for his crew. Employee #1 lost his balance and fell forward through the rubber covering that was being installed and the skylight opening. The Azusa Police Department reported the accident to the Division (Cal/OSHA) on July 24, 2011. It was determined that the employer did not ensure employees were protected from falling through the skylight opening.