Abstract: At approximately 12:25 p.m. on March 2, 2009, Employee #1 was working for an oil well service company on a rig. As Employee #1 was spreading sawdust onto two fan belts that were driving the rig's hydraulic pump, one of his hands became caught between the slave pulley and V-belt. The fifth digit of Employee #1's hand was amputated. Employee #1 was taken to Memorial Occupational Medicine, where he received treatment for his injury. The incident investigation revealed that when water from the hydraulic pump contacted the V-belts, friction was lost between the driver and slave pulleys, causing them to malfunction.