Abstract: Employee #1 and coworkers were performing maintenance on the metal surfaces of an asphalt plant's bag house when a storm began approaching the plant. The supervisor gave orders to gather the equipment and descend a caged access ladder that ran from roof to ground level. All employees were off the bag house roof except Employee #1, who was untying a compressed air line that had been secured to the guardrail system and ran around the perimeter of the roof. Employee #1 fell about 29 ft from the roof, landing on his back with his feet toward the bag house. He sustained multiple fractures. No one admitted to seeing him fall off the roof. It could not be established if he was on the outside of the standard railing prior to the mishap or if he fell over or between the railing because of high winds. There was no evidence that lightning struck the bag house immediately prior to Employee #1's fall.