Abstract: At 10 a.m. on October 20, 2021, an employee was working for a landscaping service. About eight days earlier, the service had purchased a 2021 CMC 92HD+ Arbor Pro lift, with serial number S21A3110. The vendor had agreed to provide a trainer to come from another state if the employer paid travel expenses of some $2,000. While the employer was waiting for the trainer to be available, the firm put the lift to use. Because the employee had experience on similar lifts, he was using the lift. The firm's owner believed that his experience included this type of lift. The only one permitted to operate the lift was the employee, because of his experience. The employee was wearing a harness and had attached the lanyard to the lift's anchor point. He had set up the lift straddling a street curb, with two feet on the street and two feet on the ground. He was on about the fourth setup or lift of the day. All previous lifts that day had been about 30 feet (9 meters) high to trim trees, using the setup of two feet on street and two feet on ground. This lift was for taking down a tall, large tree located in a bowl or ditch next to the street. The tree was about 100 feet (30 meters) tall. The employee was going to cut and remove limbs before felling the trunk. He had extended the boom out horizontally and vertically to its maximum, approximately 90 feet (27 meters) to get to a limb. The basket started to move in a direction that was not intended by the operator. The feet of the lift on the street started to rise. The lift's alarm sounded, indicating that the lift was no longer level. The lift fell over and slid or fell down an embankment into the bowl or ditch. Markings on the ground showed that a foot or feet left a depression in the ground before the lift fell over. At around 45 feet (14 meters) high, the lift's boom or basket caught on a tree and slid down the tree, slowing the fall. The employee suffered compression back fractures. He was hospitalized.