Abstract: At 9:30 a.m. on February 17, 1997, Employee #1, of Western Drilling Inc., was in the drilling rig collar. A coworker told him to break out the piping on the wellhead. Employee #1 used a hammer to break the chuck valve union. The line was under pressure and water sprayed out. Employee #1 tried to screw the union back on, but could not seal it. He then closed the valve. Pressure built up, and the hose broke, the threads of the nipple to the chuck valve tore out, and the valve came loose, striking Employee #1. He sustained a serious fracture of his lower right leg, for which he was hospitalized.