Abstract: At 2:45 a.m. on January 3, 2020, an employee was working for a firm that manufactured miscellaneous electrical equipment and components. He worked as a maintenance technician. He was repairing the facility's automatic coil assembly machine number 8, in the assembly area. The machine was powered by more than one energy source. It had a source of pneumatic energy, compressed air at 87 psi (600 kPa), and a source of electricity, at 208 volts three-phase. Employees performed maintenance and testing on different machines in the facility on a daily basis. In addition, employees also performed testing in conjunction with the maintenance activities. During maintenance or testing, typically a machine was placed in manual mode, but it was not locked out, and the power remained on. The coil assembly machine was hardwired into its power supply. In this incident, the turntable of the automatic coil assembly machine activated while the employee was performing maintenance. The employee's arm was pinned between the turntable and the machines post. The employee's arm was broken, and the employee was hospitalized as an inpatient. Technicians were in the habit of placing the machine in manual mode to test the machine operations prior to and after repairs. Employees stated that it was more convenient to leave the machine on. The firm's maintenance supervisor and operations superintendent were aware that employees performed repairs on this and other machines by placing the machines in manual mode, which bypassed interlock guards. Both were aware that machines were typically not locked out during maintenance. Employees were not aware of any specific lockout/tagout (LOTO) procedures.