THE BACK LEFT TIRE WAS DEFECTIVE (STEEL SHOWING) CAUSING THE DRIVER TO LOOSE CONTROL AND RUN ACROSS THE S/B LANE OF TRAFFIC AND STRUCK A GUARDRAIL, THE VEHICLE THE OVERTURNED GOING OVER THE GOUARDRAIL DOWN INTO A CREEK BED, THE VEHICLE THEN FLIPPED REAR OVER FRONT ONE COMPLETE TIME, ALL 4 OCCUPANTS WERE INJURED (BRIDGESTON/FIRESTONE P235/75R15, RADIAL ATX M/S, VDHL1M0254, LEFT REAR). NLM