Abstract: A four-man crew was removing flue gas tubes from inside an air preheater using cutting torches. An air intake shaft was 7 ft from where Employee #1 and a coworker were working. The supplied lighting was not bright enough to illuminate the open shaft. Employee #1 was apparently moving an unused portable lamp toward the open shaft to protect it from falling debris when he stepped into the air shaft and fell 20 ft. By the time the fire department and others retrieved Employee #1 from the bottom of the shaft, he was dead. The air preheater was considered a permit-required confined space. The opening to the air shaft at the 20 ft level was not guarded.