Employees were working on a brush mower that was elevated on the forks of a skid steer. The fork carriage became dislodged from the skid steer causing the brush mower deck and fork implement to fall injuring three employees. Employee 1 was hospitalized with head injuries. Employee 2 was hospitalized with a broken ankle requiring surgery. The third employee three was treated for a sprained thumb and knee and fractured vertebrae and released.