Abstract: A rail inspector for a transit authority was working on a circuit-modification project. The project included dividing a 750-volt dc bus into two sections, north and south. The inspector opened the circuit in the rail-yard substation, but he did not lock it out or tag it. After testing the bus with a voltmeter, he used a scissor lift to reach a junction box. As he was removing the bolts for the junction box cover, he received an electric shock and sustained third-degree burns to his left hand. The employer's accident investigation team reported that there was a possibility that the bus was accidentally energized by a combination of a knife switch for the disconnect switch being in the closed position and a fault in the control wiring to activate the contactor in the disconnect switch.