PERSONAL FRIEND/TRUCK DRIVER WAS DRIVING 2004 FREIGHTLINER COLUMBIA WITH MERCEDES ENGINE ON INTERSTATE HIGHWAY. OTHER MOTORIST SAW HIM DRIVING ERRATICALLY, AND CALLED POLICE. DASH CAMERA RECORDS HIM WEAVING IN THE ROAD AND FINALLY VEERING INTO ONCOMING LANE, CRASHING INTO CONCRETE BARRIER. IMPACT WITH THE WALL CAUSES FUEL TANK TO SEPARATE FROM CAB, CAUSING SMALL FIRE WHICH DID NOT BURN DRIVER OR CAB. DRIVER WAS PRONOUNCED DEAD AT THE SCENE. AUTOPSY REVEALED SIGNIFICANTLY HIGH LEVEL OF CO IN BLOOD (61-65 %), BUT NO HEART ATTACK OR STROKE OR ANY OTHER NATURAL CAUSE. DEATH IS RULED ACCIDENTAL. FORTUNATELY, THERE WERE NO OTHER SERIOUS INJURIES, BUT MANY OTHERS COULD HAVE BEEN KILLED. THERE IS APPARENTLY A PROBLEM WITH THE EXHAUST SYSTEM ON THIS VEHICLE, AND OTHERS WILL DIE UNLESS THIS PROBLEM IS CORRECTED. *TR