Abstract: At approximately 10:00 a.m. on December 28, 2011, Employee #1, a 32-year-old male with Bushwackers Tree Service, was at a jobsite in Kings Beach, CA. Employee #1 had just started working for the Employer but had many years of climbing experience. Approximately three Employees were working on the job for two days. The incident occurred on the first tree of the second day. According to Employee #1, he would climb up to the highest point and then he would limb his way down. While he was climbing up the tree, the clip on his flip-line became entangled in a small branch, causing it to come open. When a branch he grabbed was unable to hold his weight and loaded the flip-line, it caused the clip to come loose and Employee #1 to fall approximately thirty-feet to the ground. Employee #1 had not yet tied into his safety line or climbing line. Employee #1 had planned to tie into once he got to his working point. The employer had an Injury Illness Prevention Program including training specific to the hazards associated with tree work. The tree work was being performed under the direction of a qualified tree worker and had been inspected prior to the start of work. The climbing equipment had been inspected prior to the start of work. The employer was a tree trimming company.