Abstract: Employee #1, a construction supervisor, and a coworker were evaluating the condition of the roof of a cooling shed adjacent to a lumber kiln. The wood surfaced was constructed of 2 by 10 stringers set on 24 in. centers, with 1 by 6's for the decking. Roll roofing material had been placed over the top. The roof, which was approximately 24 ft high in the center, had some holes and a dark motley coloration from the effects of steam emitted from the kilns and dust accumulating on the wood. To better evaluate the roof, the two employees accessed the flat kiln roof through the instrument room. While standing on the kiln roof, they used a hammer and pry bar to remove some of the roofing material and to gouge a hole in the shed roof. The 2 by 10's were slightly deteriorated; the 1 by 6's appeared to be solid on the outside but were completely rotten inside. The two employees then stepped onto the cooling shed roof. The coworker stayed near the edge while the supervisor walked on a stringer to near the center of the of the domed shed and checked another spot by hitting the decking with the hammer. He was turning to exit the roof when he fell through the decking to the ground, which was lined with iron rails for moving lumber cars out of the kiln. Employee #1 sustained fatal internal injuries.