Abstract: At approximately 6:30 a.m. on October 17, 2012, Employee #1 was instructed by his supervisor during an early morning meeting to remove the barricade railing on the second floor and extend the railing outwards towards the center of the building. This job site was at the north end of building Hilltop E. The railings were being moved in order for the stonecutter to cut a hole on the concrete floor where the railing was located. The employee asked a coworker to go to the first floor below and put caution tape barricade on the area where the stonecutters will be cutting the floor so that no other employees would be exposed to the falling debris hazards. According to Employee #1, the supervisor did not inform him that there was a floor opening in that work place vicinity, nor did he inform him to wear fall protection. The barricades railing did not go all the way around. The employee stated that only two sides of the floor opening were barricaded instead of all four sides. The employer stated that the accident scene was not disturbed and preserved until CSHO arrived. There was no evidence that two other railings were installed to guard the two remaining openly exposed sides of the floor opening. Employee # 1 worked alone as he commenced to remove the railings. As he removed his first railing, he stepped into a piece of plywood that tilted on to a floor opening. A grey plastic sheet that concealed the floor opening covered the floor opening. Employee #1 slid on the plywood and fell through the floor opening breaking the grey plastic and falling to the first floor approximately 15 to 20-ft below. The employee was transported to an area hospital, where he was treated for multiple head and body fractures. Employee #1 remains hospitalized.