Abstract: At 9:00 a.m. on October 3, 2019, an employee working as a contractor was assigned to work at a waste energy generation site to remove some ash. The ash had accumulated on the roof of an ash house. The employer had a work crew on site using a wet/dry vacuum truck to perform the work. The employee was using aluminum piping to remove the ash and was wearing PPE. The employee was working with coworkers in an alleyway next to the ash house, which was adjacent to the pump truck location. The employee was assisting coworkers with vacuuming the ash material from the roof of the structure when they realized that there was a blockage. The crew shut down the equipment to locate the blockage which was determined to be in the vertical section of pipe that ran from the roof to the alleyway below. Coworkers were separating two sections of 10-foot by 6-inch pipe in order to lower them and locate the blockage. The employee had disconnected the lower section of piping when it shifted. He instinctively reached out to stabilize the pipe when the pipe shifted downward and struck his arm. The employee incurred a compound fracture to his right forearm and was hospitalized requiring surgery.