I AM AN INDEPENDENT CONTRACTOR TO CR ENGLAND. WHILE SOUTHBOUND ON I-77 TOLL ROAD 000.2 MILES SSW OF GALLAGHER WV APPROX. 20:54:00HRS I SMELLED HEAVY EXHAUST GASSES WHEN PAUSED BACK AT THE TOLL BOOTH. I ATTRIBUTED THIS TO A VEHICLE IN FRONT THAT WAS OUT OF TUNE AND CONTINUED SOUTH. THE ODOR DID NOT GO AWAY SO I PULLED OVER TO THE HARD SHOULDER TO INVESTIGATE. AS I MOVED INTO THE SHOULDER THE DASH LIGHTS LIT UP AND FLASHED. I APPLIED THE BRAKES AND OPENED THE DRIVER SIDE DOOR TO CHECK THE CRACKLING NOISE COMING FROM BEHIND THE FIREWALL. SMOKE AND FLAMES WERE COMING FROM BENEATH THE BODY BETWEEN THE DRIVER SIDE FUEL TANK AND DOOR. I IMMEDIATELY CLOSED THE DOOR, SHOUTED TO MY SLEEPING STUDENT TO GET OUT WE ARE ON FIRE. HE BEGAN TO GATHER HIS THINGS BUT I TOLD HIM TO GET OUT NOW WHICH HE DID IN HIS UNDERWEAR AND A BLANKET. I FOLLOWED HIM OUT THE PASSENGER DOOR, PAUSED AND REACHED IN TO GET MY PHONE. I LOOKED UP AND SAW BILLOWING BLACK SMOKE FILLING THE TOP OF THE CAB SPACE AND DESCENDING DOWN RAPIDLY. WE WALKED TO THE END OF THE 53 FT TRAILER AND 10 MORE FEET ON THE PASSENGER FUEL TANK EXPLODED AND THE REST OF BOTH VEHICLES QUICKLY WERE ENGULFED AND LOST. NO BODY COULD EXPLAIN WHY THIS HAPPENED UNTIL I BECAME AWARE OF THE RECALL 12C (?), APRIL 2013, ON THE FUEL FEED ASSEMBLY FROM THE FUEL PUMP THROUGH TO THE INJECTORS VIA THE INDIVIDUAL INJECTOR LINES. I ASSUME THAT THESE WERE OVER-TIGHTENED EITHER IN ASSEMBLY IN SALTILLO, MX OR, IN SERVICE OR OTHERWISE AT COMPANY SH