2 PIPEFITTERS WERE ASSIGNED TO REMOVE A VERTICAL3"" PIPE PROTRUDING FROM THE FLOOR OF BLDG. 1 USED A PORTABAND SAW TO SEVER THE PIPE AT ITS BASE WHILE THE OTHER WATCHED. THE TOP OF THE PIPE WAS UNATTENDED AS THE CUT WAS COMPLETED THE PIPE TOPPLED THE EE WATCHING PUSHED THE EE CUTTING OUT OF THE WAY THE PIPE STRUCK THE WATCHERS' LEFT FOOT