Abstract: At approximately 9:30 a.m. on June 19, 2001, Employee #1, a carpenter and a coworker worked on putting up the second-floor roof at the construction of Ballona Creek Center, located in Culver City, California. Employee #1 arrived at the site at about 8:00 a.m. After attending a job safety meeting, he cleaned the area. The superintendent requested the framers to mark the arched beams at 4 ft on centers for the welders. Employee #1 and a coworker started out to mark the overhead arched beam radiuses at 4.5 ft, covering an area 76 ft long in the East-West direction and 38 ft long in the North-South direction. The center of the arch was about 23 ft from the floor below. Employee #1 used the top platform of the 25-ft-high rolling tower scaffold to reach out the beams. He marked the beams, starting out from the middle of the North-West side. When Employee #1 did as much marking as he could from that position, while on the scaffold, he asked the coworker to move the scaffold towards the East to the next row of beams. While the coworker was moving the scaffold, one of the casters of the wheel went through a hole on the plywood floor. The scaffold got imbalanced and started to tip over. The coworker shouted to warn Employee #1. Employee #1 panicked and jumped down to the plywood decking located 25 ft below. He landed on his left shoulder. The entire scaffolding collapsed. Employee #1 sustained fracture of his left arm at distal radius. He was transported to the University of California, Los Angeles Medical Center. Employee #1 had worked as a carpenter for the framing contractor for approximately eleven-and-a-half years. The primary duty of Employee #1 was to do carpentry work, like cutting beam, nailing, putting joists, sheathing, and other tasks as instructed by the company. It was evident that the serious injury was due to the Employee #1's riding the rolling tower scaffold.