Abstract: At approximately 8:00 a.m. on May 8, 1991, Employee #1, of Mule Creek State Prison, observed that the primer switch on the meat stuffer machine was not operating. He reported this to his leadsman, who advised him to prime the stuffer machine horn by rotating the carriage of the adjacent poly-clip machine. At approximately 10:30 a.m., Employee #1 cleaned and reassembled the air piston and horn. He primed the horn and was attempting to catch about 8 1/2 pounds of sausage meat when his finger entered the sealing and displacement zone, where the descending staple driver amputated part of his right index finger. After the accident, the employer obtained 'Do Not Operate' tags and instructed workers to tag machines when they were not functioning properly and to cease operation.