An employee was asked to help perform maintenance on a die cast machine. The employee entered the work area, got into a kneeling position, and began using an open-end wrench to remove a hydraulic hose so a fitting could be repaired. When the hose came free from the fixture, residual hydraulic pressure released and hydraulic fluid struck the employee in the chest. The employee fell backward and struck his head on surrounding machinery. The employee was hospitalized with a subdural hematoma, fractures to the forehead, orbital area, and ribs, and required stitches for a forehead laceration.