Inspection Detail

Inspection: 310197728 - City Of Los Angeles Bureau Of Street Services

Inspection Information - Office: Van Nuys District Office

Investigation Summary

At approximately 9:21 a.m. on June 8, 2007, Employee #1, a tree surgeon, was repelling down a line attached to an aerial boom. Normally, he uses an aerial boom to trim trees for a local city government. On this particular day, Employee #1 and his supervisor were attending a career day fair at an elementary school, demonstrating common procedures used to escape an aerial bucket that was stuck. He elevated the Altec truck boom (Serial Number 377-17419, Model Number A650L) and bucket to 55 feet in height through his own controls, while his supervisor was on the ground. Employee #1 was wearing a tree climbing saddle with a ball locking Petzl William carabineer (Pat. 25 KN and 7 KN, CEO0197, 05289H) attached. A figure 8 knot, that provides the braking force to control speed of fall, was attached to his carabineer, which he verified both by feel and sight. The line for Employee #1 to descend the bucket then ran through the figure 8 knot. As he descended, the figure 8 knot separated from the carabineer, causing Employee #1 to fall at a much quicker rate, only able to control his speed by using his gloves. He landed on his feet at the high rate of speed, breaking his right ankle and injured his back. Employee #1 was hospitalized and treated for his injuries. During the accident investigation, it was reported by Employee #1's supervisor that the carabineer was open after Employee #1 hit the ground. Upon closer examination, it was observed that the sleeve of the locking mechanism was twisted.

Keywords: FRACTURE, STRUCK AGAINST, EQUIPMENT FAILURE, BACK, FALL, LOGGING, TREE TRIMMING, ANKLE, LEG