Abstract: A lineworker for an electric cooperative was replacing a step voltage regulator for the "C" phase of a power line energized at 7,620 volts phase-to-ground. The regulator was capable of operating at 438 amps. The line was supposed to be deenergized for the operation. Each of the three phase conductors had its own regulator, and system neutral was connected to all three of the regulators in the regulator bank. The neutral connection started at the "A"-phase regulator and proceeded by a wire to the "B"-phase regulator. Then, a separate wire connected the "B"-phase regulator to the "C"-phase regulator. A separate wire connected the regulator neutral to the overhead system neutral. For the work being done, the "B"- and "C"-phase regulators were bypassed, while the "A"-phase regulator was left operational. Thus, the neutral line was carrying current through all the regulators to make a path for the "A"-phase regulator's regulating current. None of the lines (line, load, or neutral) leading to or emanating from the regulators were tested or grounded, nor were such steps required, according to the employer's training, actual practices, or written procedures for changing out regulators. The line and load wires were taken off the regulator without incident. When Employee #1, standing on a ladder, disconnected the current-carrying neutral line, an arc occurred, according to other workers. He fell, hitting his head and chest hard, breathed for a short period, and died after CPR attempts. The coroner determined that the cause of death was electrocution.