DRIVER HAD JUST SCALED OUT HIS LOAD & PULLED AHEAD OF THE SCALE APPROX 117' ALONG THE ROADWAY EAST OF THE PACKHOUSE BLDG. ANOTHER TRUCK FOLLOWED BEHIND HIM ONTO THE SCALE. HE STATED HE SAW DEC EASED PULL HIS RIG OFF TO THE RIGHT SIDE OF THE ROADWAY ON A SLIGHT INCLINE. DECEASED WAS OUT OF HIS TRUCK AT THE REAR LOOKING INTO THE RAISED BED OF UNTARPED MATERIAL. TRAILER WENT OVER.