Abstract: At 4:20 p.m. on April 9, 2004, Employee #1 was a machine operator-in-training, at a facility in Riverside, California, who was cleaning the right side height pin on Machine #6, a Besser Dynapac concrete block forming machine. Employee #1 was attempting to wipe the height pin with a paper towel, while the machine was still running, when his middle and ring fingers on his left hand were caught between the height pin and its stop. When Employee #1 withdrew his hand, a portion of his left middle finger tip remained with the machine. Employee #1 was transported to an occupational medicine clinic and then to the Riverside Orthopedic Medical Group where, during surgery, the physician had to remove a portion of the damaged bone at the tip of Employee #1's left middle finger.