Abstract: A line-clearance tree trimmer was working with a ground worker and a supervisor, performing a line-clearance tree trimming operation. At about 10:25 am, the crew went to a new area. The tree trimmer parked his aerial lift truck below a 13-kilovolt overhead power line, and the supervisor parked his truck behind the aerial lift truck. The supervisor and ground worker placed traffic cones. Then, the ground worker started the auxiliary motor powering the aerial lift and outriggers. He lowered the outrigger on the passenger side of the truck, and the supervisor lowered the outrigger on the driver's side. The tree trimmer climbed into the aerial lift bucket and began elevating it. The supervisor went to fill a chainsaw with gasoline and did not watch the tree trimmer. The ground worker stood about 1 meter from the passenger-side outrigger and watched the tree trimmer. The tree trimmer was facing the aerial lift controls without watching the overhead power line, which was located behind him. He contacted the phase conductor with his head as his lower back contacted the neutral conductor. The ground worker warned the tree trimmer just before he contacted the power line, but it was too late. The tree trimmer was electrocuted. The tree trimmer and ground worker had not been fully trained regarding their respective job assignments. Additionally, the supervisor did not conduct a job briefing for the new location.