Abstract: At 10:00 a.m. on September 14, 2021, an employee working as an HVAC repair technician for a city water plant was performing preventive maintenance on an air handler unit (AHU). The employee worked for the employer as a full-time employee. The employee was working alone on the DIE-2901-00004 Fan Exhaust Unit Digester 8E. He was working on energized equipment. The employee was listening to the machine and heard a noise from the unit. He went close to unit and bent over to look at the machine placing his right hand on the cover. The employee was wearing gloves at the time. The employee lost his balance and caught his glove in the belt and pulley. His supervisor was not at job site at the time. The employee was hospitalized to treat an amputation to his thumb.