EE WAS ASSISTING IN MAINTENANCE PROJECT. A 2 15/16"" SHAFT WAS LIFTED ONTO THE TAILGATE OF A PICKUP, AND A MECHANIC WAS REMOVING A TAPER LOCK BURSHING. THE INJURED EE WAS STANDING IN THE PROXIM ITY WHEN A SMALL CHISEL, BEING USED TO SPREAD THE TAPERLOCK SUDDENLY FLEW OUT STRIKING THE INJURIED EE.