Abstract: At approximately 1:30 p.m. on August 27, 1990, Employee #1 was preparing to top an aspen tree. He had climbed approximately 65 to 70 ft, using climbers and a safety belt equipped with a flipline, and removing limbs as he ascended. The foreman then told Employee #1 to tie off and prepare the tree for topping since it was to be removed in sections. The foreman then walked to another tree approximately 30 ft to the west. While the foreman was studying the second tree, he heard Employee #1 start his chain saw and then heard a thump. When the foreman went back to the first tree, he saw Employee #1 lying face down, approximately 7 ft from the base of the tree. The foreman could feel no pulse and ran up the road looking for help. He found two forest rangers, who contacted the Sheriff's Department and requested medical assistance. Employee #1 was killed. Subsequent investigation revealed that the rope used by Employee #1 as a lifeline had been cut at its center, approximately 18 in. from the safety belt hook. Employee #1 also had another rope, which was supposed to be used as his safety line, attached to his belt, but he had not used it. Rope fibers were found in the teeth of his chain saw. However, it is not known why Employee #1 had not tied off with the safety line as instructed by the foreman, or why he had started the chain saw again.