A 44-year-old male tree faller/bucker (the victim) was felling and bucking (cutting into specified lengths) timber on a mountainside with a 67 percent slope. The victim felled a hemlock tree which came to rest across another hemlock that he had previously felled. Both logs were lying almost parallel with the slope contour. The victim removed the tree limbs from the second hemlock, then measured and marked the log for bucking into sections. After bucking off two sections of the log without incident, he bucked off a third section, which allowed the log's heavier end to pivot down slope. The lighter end of the log swung up slope and fatally crushed the victim against the first hemlock. NIOSH investigators concluded that in order to prevent future similar occurrences, employers should: 1. ensure that fallers and buckers properly evaluate felled trees to be bucked, and the area around them so that potential hazards can be avoided; 2. ensure that fallers and buckers prepare an adequate escape path before attempting to buck any tree; 3. ensure that fallers and buckers receive adequate training in safe work procedures; and, 4. conduct inspections to ensure that workers follow company safety procedures.