Abstract: Employee #1 was operating a loader while sitting adjacent to the boom (over the drivers cab). Employee #1 started to pick up logs one at a time and loaded them onto the flatbed using the grapple. Employee #1 then picked a large log, approximately 23 ft. The flatbed truck was equipped with hollow 4-in. steel square extensions that could slide onto the sides of the flatbed to prevent the logs from becoming displaced during transporting. The top of these extensions were approximately 12.5 ft off of the ground. The log needed to be lifted over 12.5 in. to clear the extensions to be placed on the back of the flatbed. Employee #1 had difficulties lifting the log and needed to maneuver the load to get it over the extensions. After the load was lifted over the extensions, but before the log was placed on top of the other logs, the mast (turn table) steel was sheared just below the main boom pivot. The boom crane came down on top of Employee #1 as he was sitting in the chair. Employee #1 was hospitalized, and treated for his injuries.