Abstract: At 8:00 p.m. on November 8, 2021, an employee, a maintenance worker, was troubleshooting a machine that was experiencing an issue with an oil pump. The employee removed a back guarding panel from the Mecal Kosmos CNC machine in order to observe the oil pump on the rear of the cutting head. The employee grabbed a ladder to be level with the pump and observe it as the machine functioned. The employee stumbled on the ladder and his arm went into the opening of the machine where the guard had been removed. As the employee's arm went into the opening, the CNC cutting head was returning to the home position on the right side of the machine. The cutting head pinched the employee's arm between the cutting head and the backside of the guarding wall causing a fracture to both the radius and ulna of his arm. The employee was hospitalized to treat a fractured arm.