Abstract: Employees #1 and #2 were welding from the top level of a 20 ft 6 1/2 in. high by 5 ft wide by 7 ft long Lynn mobile propelled tubular welded scaffold. As the employees were repositioning themselves on the scaffold, it collapsed. Employee #2 attempted to hang on to the overhead joist, but fell approximately 23 ft before help could get to him. He landed on top of Employee #1, who had fallen with the scaffold. Both employees were hospitalized with fractures. The investigation found that there were no locking pins in the section connectors, and that there was no structural failure of parts. The scaffold was not equipped with a ladder access or guardrails. The employees were provided with a safety belt and lanyard; however, no fall protection was in use at the time of the accident. Employees #1 and #2 were wearing hard hats, work boots, welding clothes and gloves. No competent person inspected the scaffold.