Abstract: At approximately 1:00 p.m. on November 1, 2007, Employee #1, a salesman, and a coworker/technician, were engaged in preventative maintenance of the HVAC system for a commercial building. The units were located on the roof, which was shared between Buildings A and B. There were 13 unguarded skylights on the roof of Building A and 15 unguarded skylights on the roof of Building B. Employee #1 was apparently hosing coil cleaner compound off the Building B side of the roof when he lost track of his position. He stumbled onto a skylight, broke through the shell, and fell approximately 30 ft to the concrete floor. Employee #1 was transported by ambulance to an area hospital, where he was pronounced dead due to multiple traumatic injuries.