Abstract: At approximately 9:00 a.m. on April 30, 2008, Employee #1, a superintendent of ER1 at the jobsite, was working on the second floor of a church construction site in Chino Hills, California. He stepped on a temporary floor cover of one of the floor openings and fell 19 ft 3 in. to the concrete floor. Employee #1 sustained a fatal multiple blunt force trauma. A Medical Engine Number 66 from the Chino Valley Fire Department arrived on scene and provided emergency aid to Employee #1. The ambulance arrived at the scene and transported Employee #1 to the Chino Valley Medical Center, where he was pronounced dead minutes later. The floor opening was 44.5-in. by 48 in. and was designed for vents and ducts of a heating, ventilating and air conditioning system plan. The floor cover was made of two pieces of plywood, approximately 43.875-in. by 24-in. by 0.75-in., butted together and fastened into the 2 by 4 wood support. The 2 by 4s were fastened into the metal closure plate using three 2-in. Tec screws on each of four sides of the hole. A smaller piece of plywood, 8.875-in. by 24-in. by 0.75-in. joined the two pieces of plywood together on top center.