EE WAS IN THE MAINTENANCE SHOP HELPING TWO OTHEREMPLOYEES WORK ON THE CYLINDER OF A LOADER. THEYWERE TRYING TO TURN A 4"" NUT ON THE CYLINDER USING A 4"" PIPE ON THE END OF THE WRENCH TO HELP TU RN THE NUT. THE NUT CAME FREE AND THE PIPE FELL OFF OF THE WRENCH AND HIT TOP OF INJURED'S FOOT.