Abstract: EMPLOYEE #1 WAS APPARENTLY DISASSEMBLING THE BOOM OF A 65' LATTICE BOOM TRUCK CRANE-MODEL 430-TC 30-TON P&H.HE WAS WORKING ALONE UNDER THE BOOM WHICH WAS APPROXIMATELY 3'-4' OFF THE GROUND WITH NO SUPPORTING TIMBERS UNDERNEATH IT. IT IS STRICTLY AGAINST COMPANY PROCEDURE TO BE DOING THIS WORK ALONE AND ALSO TO BE PHYSICALY WORKING UNDER THE BOOM WHETHER OR NOT IT IS SUPPORTED. THE EMPLOYEE HAD APPARENTLY EASILY REMOVED THE BOTTOM PIN NEAREST HIM BETWEEN THE MIDDLE AND END SECTIONS AND HAD STOOPED DOWN UNDER THE BOOM ATTEMPTING TO KNOCK OUT THE BOTTOM PIN ON THE OPPOSITE SIDE. THIS PIN APPEARED TO HAVE BEEN LIBERALLY SPRAYED WITH LUBRICANT.THE PENDANT LINES WERE ATTACHED TO THE END SECTION OF THE BOOM PROVIDING TENSION ALONG THE ENTIRE BOOM AND WHEN THE 2ND PIN WAS REMOVED THE BOOM,WHICH WAS HINGED AT THE TOP BY TWO PINS,DROPPED DOWN ACROSS THE BACK OF THE EMPLOYEE CRUSHING HIS CHEST. HE WAS ASPHYXIATED. AT THE TIME OF THIS ACCIDENT HE WAS WORKING AT ONE OF HIS REGULARLY ASSIGNED TASKS.