Abstract: At approximately 1:50 p.m. on October 7, 2008, an employee was in a horizontal duct to inspect the grinding work which had been done to the shipping stops on the louvers of the duct. After ascertaining that the grinding was done properly the employee noted that he wanted to check on the factory installed refractory on the stack side of the louvers. The employee was told that any problem in that area was a factory installed problem and not his concern; however, he insisted and asked for a screwdriver. He then apparently proceeded to the area where the horizontal duct met the chimney stack and fell 40 feet into the stack. The employee's body was discovered on the ground level of the chimney stack with his body harness and lanyards intact and, apparently, unused. There were no witnesses to the actual fall as the coworker had crawled out of the duct as the employee went to the stack side.