Abstract: Employee #1, a millwright with Sierra Pacific Industries, was checking some air valves on an optimizer saw at the sawmill. He said that he had tested air valves on the #5 and #4 positions and was walking to the #3 position when his foot slipped off the raised transfer chain, causing him to fall against the chain with his chest. His chest was fractured. The transfer chains are in a race way 4 to 5 inches above the floor so lumber will not hang up on the floor. These transfer chains carry lumber to the optimizer saw to be cut to narrower widths. Employee #1 said the area that he was walking in was clear of lumber and debris. Employee #1 is not sure why his foot slipped, but suggests that he may have stepped in some oil or diesel fuel earlier.