Abstract: At approximately 1:30 p.m. on April 4, 2011, Employee #1, a Maintenance Worker was using a Bosch 7.25 in. portable circular hand saw (Model Number: 1677M; Serial Number: 488 612469) to rip a 2 by 4. It kicked back and amputated his left thumb. Employee #1 was at a residential property owned by the employer's son working on a kitchen remodeling project. Employee #1 was holding the 2 by 4 at a near vertical angle with his left hand and set it on another piece of wood on the floor. His left hand was behind the blade as it was cutting when it kicked back and went over his thumb. A coworker was in the kitchen working on the walls and facing away from the employee. The saw involved in the accident was in good mechanical shape with a properly functioning guard. The coworker called the supervisor, who told him to take Employee #1 in the company truck to Memorial Occupational Medicine for treatment. The accident was reported to the Fresno District office by the employer on April 4, 2011 at 6:31 pm.