An employee was operating a forklift to return a scrap hopper after dumping material. After the employee placed the hopper outside the aircraft hangar door, the employee noticed the hopper rolling toward the doors. The employee exited the forklift to stop the hopper and grabbed the top of the hopper. During this time, the forklift started rolling forward and struck the hopper, pinning the employee s right hand between the forklift mast and the hopper and resulting in hand fractures.