Abstract: At 12:01 p.m. on October 19, 2010, Employee #1 suffered multiple fractures when his right leg was struck by an auger extension that separated from the auger head. Employee #1 was working at a residential construction site located in Los Altos, California. Employee #1 was employed by RCM Concrete. According to the Foreman/Supervisor (Employee #2), he and Employee #1 had been drilling holes for the retaining wall using a Bobcat (loader) with an auger and a six foot auger extension. Employee #2 was operating the Bobcat and Employee #1 was the spotter, working near the drill area. Employee #2 had completed drilling holes, so he instructed Employee #1 to remove the screw locking the auger and the extension. The connection was too tight so that the screw could not be removed by Employee #1. Employee #2 instructed Employee #1 to remove soil and dirt around the auger and extension connection. Employee #1 used his hands to remove the dirt around the auger/extension connection and to remove or loosen the screw holding the extension and auger. Employee #1 said the arm of the Bobcat suddenly moved while he was still working on removing the screw. The movement of the arm of the Bobcat separated the auger extension from the auger. According to Employee #1, he was struck by the auger extension and he was thrown on the ground approximately 10 to 15 feet away. In an interview, Employee #2 stated that he could not see how the extension connection to the auger head was angled, so he asked Employee #1 to give him a hand signal. Employee #2 said he moved the Bobcat arm forward after getting a signal from Employee #1. Employee #1 was standing less than a foot away from the auger extension. As Employee #2 moved the Bobcat arm forward, the auger extension became separated from the auger and it swung toward Employee #1, injuring his right leg and resulting in multiple fractures. Employee #1 also suffered a scalp laceration. Employee #1 was taken by ambulance to Stanford Hospital in Palo Alto, California where he was hospitalized for 5 days.