Abstract: An employee was performing maintenance work on a boiler at an electric power generation plant. He was assisting a welder in attaching a midrail at the side of a platform. The employee was walking rapidly along the painted surface of a 12-inch-wide steel I-beam. The I-beam was protected on the left side by the boiler and on the right side by a wire rope suspended 41 inches above the I-beam by stanchions. There was no midrail, nor was the employee using any personal fall protection equipment. When he reached the end of the I-beam, he turned 90 degrees to the left to traverse a 12-inch-wide wooden plank spanning a gap between the beam and a working platform. The employee stumbled, fell, and rolled under the wire rope guardrail. He fell 51 feet to a steel catwalk, striking his head on an I-beam on the way down. He died of injuries sustained in the fall.