Abstract: Employee #1 was standing on a 29 ft high by 6 ft long by 4 ft 6 in. wide platform constructing a 34 ft 6 in. high grid ceiling when he decided to move the mobile scaffold. He called to his foreman for assistance, and receiving no response, Employee #1 attempted to pull the scaffold by tying wires to the roof bar joists, unaware that his foreman had locked all the casters. The employee's first pull upset the scaffold. Realizing that the scaffold was overturning, the employee unsuccessfully attempted to grasp a roof bar joist and did succeed in momentarily delaying his fall so that he landed on the scaffold frame and not on the concrete floor. Employee #1 was hospitalized with severe chest, abdomen, and liver injuries. Outriggers had not been attached to the scaffold. Consequently, the scaffold, at 29 ft high, far exceeded the 4:1 ratio of height to its minimum base dimension and the 2:1 weight ratio that would have allowed the employee to ride safely on the moving scaffold.