Abstract: At 11:30 a.m. on May 4, 2021, Employee #1, a groundsman employed by a tree trimming and removal service, was working with a crew of six employees to remove trees at a residential site in Grass Valley, California. Employee #1 and a coworker were standing near the base of a pine tree where a climber was positioned, removing limbs from the trunk. A second climber was positioned in a nearby pine tree to prepare for felling that tree. For unknown reasons, the second climber used a gas-powered chainsaw to cut the second pine tree at approximately its middle portion. When the tree top fell to the ground, it toppled toward the first pine tree where Employee #1 and the coworker were standing. The cut portion of the tree, approximately 40 feet in length, struck Employee #1 in the back and head, causing a concussion. The employer and homeowner contacted emergency services, and Employee #1 was transported to Sutter Roseville Hospital, where he was treated without hospitalization and released the same afternoon.