Abstract: On Saturday, January 28, 1995, Employee #1, of JDK Controls, Inc., was operating the 50-ton hydraulic press that he operates once a week. Employee #1 was making 1/2 in. wafers using a 1/2 in. tempered steel die (designed working pressure of 4 tons) that he had set up that morning. A 2 in. die had been used the previous day (working pressure of 40 tons). He had been trained to adjust the pressure up or down as pressure rises when starting the first wafer. He did this but he started the pressure adjustment in the wrong direction, raising the pressure setting to 48 tons. The die exploded at about 12 to 13 tons of pressure, sending fragments about the room. Several pieces struck Employee #1 in the face and blinded his left eye. First aid was applied and 911 was called. He was transported by helicopter to UC Medical Center in Sacramento, CA.