Abstract: At approximately 11:00 a.m. on January 15, 2014, Employee #1 and Coworker #1, employed by Inland Empire Framing Inc., were engaged in exterior carpentry at a project to construct new single family residences. Employee #1 was operating a Hitachi 16 pennyweight pneumatic nail gun while framing the roof rafter overhang fascias. According to the subsequent investigation, Employee #1 sustained a puncture wound and a fractured right femur when he inadvertently struck his right leg with the muzzle of the nail gun while his finger was on the trigger, causing a 16 pennyweight, 3-inch long nail to be driven into his femur. Coworker #1, who was Employee #1's immediate supervisor, transported Employee #1 to Pasadena Community Urgent Care Center. From there, Employee #1 was transported by ambulance to Huntington Memorial Hospital. Coworker #1 met Employee #1 at the hospital and stayed with Employee #1 in the emergency room until 8:00 p.m. on January 15, 2014, in the belief that Employee #1 would be treated and released. However, on January 16, 2014, the employer learned that Employee #1 had been admitted to the hospital, had undergone surgery to repair a fractured femur, and would remain hospitalized for at least two more days. The employer reported this event to Cal/OSHA at 2:38 p.m. on January 16, 2014. Cal/OSHA began its investigation at the worksite at 1:25 p.m. on February 3, 2014. The investigation determined that Employee #1 was a piecework carpenter assigned the routine task of completing the exterior roof rafter fascias on the lookout of the single family residence being built on lot 22. This task involved nailing wood pieces measuring 2 feet long by 4 inches by 6 inches into the top plates of the lookout wall and the house exterior gable fascias. The gable fascias measured 2 inches by 6 inches. Employee #1 had completed nailing one 2-foot long wood piece and was stepping over it and simultaneously nailing another wood piece into the fascia. The nail gun slipped off the fascia and inadvertently bumped into Employee #1's leg while his finger was on the nail gun trigger, causing a nail to shoot into his right thigh. According to the investigation, Coworker #1, who was Employee #1's immediate supervisor, was working on another lot and did not witness the event. The supervisor was informed that Employee #1 needed to go to the clinic, and that Employee #1 was not bleeding and was able to walk. The supervisor transported Employee #1 to the clinic and then met him at the hospital. The investigation report concluded that Employee #1 was in the habit of continually depressing the trigger of his nail gun and bumping the muzzle against the wood to shoot a nail into the wood. In this instance, a combination of Employee #1 rushing to perform a piecework job, Employee #1 slipping as he stepped over a wood piece, the nail gun slipping off the fascia, Employee #1's finger depressing the trigger, and the nail gun striking his leg resulted in this injury. At the time of this report, Cal/OSHA intended to issue a citation to the employer for a violation of T8 CCR 1704 (g) for not formally training Employee #1 on the proper use of a nail gun.