Abstract: At approximately 8:30 a.m. on October 26, 2012, Employee #1, of Bay Air Systems, Inc., was working at a multiemployer construction site, a 24 Hour Fitness building. He and three coworkers were on the roof and laying out huge HVAC machinery. The machinery was being lifted by helicopter from the ground to the roof. According to Employee #1, he was standing on the corner end of the building and looking up at the helicopter, waiting for the machinery to be lowered. He moved sideways. He later reported that as he moved he felt he was stepping onto the steel cover of a 24-inch square opening in the roof. He fell through the opening to concrete below. He was transported to Eden Medical Center in Castro Valley, where he was admitted and treated for five days for serious injuries. His injuries included but were not limited to fractured ribs, fractured collar bone, and fractured spine.