Abstract: At 2:00 p.m. on November 1, 2021, an employee was performing routine maintenance on a Volvo L90E Wheel Loader in a customer's maintenance shop. The employee was replacing several hydraulic lines on the heavy equipment, including the hydraulic line to the tilt cylinder. The employee was working underneath the arm of the loader which was supported by a single jack stand. The stand had a flat surface area of about 4 inches to 5 inches which was supporting the loader frame on the front quick attach bracket. The tilt cylinder contained pressure from hydraulic fluid in the lines. Once the hydraulic line was removed from the tilt cylinder the pressure was relieved out of the hydraulic line allowing the attachment bracket to curl back. When the bracket curled back, it was slipped off of the stand causing the boom arm to lower. The employee was crushed between the arm and the frame of the loader. The employee fractured his skull, scapula, collar bone and ribs and a collapsed a lung, all on the left side of his body, and required hospitalization.