AS INJURED WAS TAKING SLACK OUT OF A 2 TON CHAINFALL THAT WAS CONNECTED TO AN OVERHEAD 8"" DIAMETER PIPE AND AN 8"" PIPE IN A COAL DISTRIBUTOR 3' UP FROM FLOOR. THE OVER HEAD PIPE FELL STRIKING HIM ON THE ARM (THE OVERHEAD PIPE WAS APPROX 12'LONG) IT WAS HELD UP IN PLACE WITH 3"" BY 3"" BY 3/8"" ANGLE WELDED TO IT AND AN I BEAM.