LEFT REAR TIRE HAD TREAD SEPARATION AND SIDEWALL CIRCUMFERENTIAL DISINTEGRATION, WITH LOSS OF CONTROL OF THE SUV. IT WAS DRY ROAD, DAYTIME, OUTSIDE TEMP ABOUT 55F, SPEED ABOUT 42 MPH, AND CAR HAD BEEN MOVING FOR ABOUT 10 MINUTES FROM COLD START. CAR CAREENED SIDE TO SIDE OF 2 LANE MEDIUM SPEED HIGHWAY, FINALLY STOPPING IN ABOUT 1/4-1/3 MILE. REQUIRED EXTREMELY VIGOROUS MUSCLE TO LIMIT LATERAL TRAVEL AND TORQUE ROLL OF VEHICLE. THE SOUND WAS LIKE A HELICOPTER ROTOR CHOP THAT BECAME RAPIDLY LOUDER OVER 5-10 SEC, FOLLOWED BY LOSS OF CONTROL. TIRE INSPECTED BY INSURANCE WHO CERTIFIED THERE WAS NO ROAD HAZARD CAUSE, AND 'HAD NEVER SEEN A TIRE DISINTEGRATE LIKE THIS BEFORE'. TIRES ARE OEM, ORIGINAL, ROTATED PER SCHEDULE, MAINTAINED PRESSURE PER LABELLING. VEHICLE HAD TWO PERSONS, NO TOWING OR LOADS MORE THAN 1-2 ADDITONAL PASSENGERS AT ANY TIME. *AK (TIRESIZE: 245-70-16)( DOT NUMBER: TIRE SIZE: 245-70-16 )