ON TWO SEPERATE OCCASIONS, TIRE TREAD SEPARATED FROM THE TIRES WHEN TRAVELING 60-65 MPH. THE TIRES ARE FIRESTONE FIREHAWK ATX 33X12.50R15LT MOUNTED ON A 1993 FORD BRONCO. ON THE SECOND OCCASION, THE TREAD SEPARATION RESULTED IN LOSS OF CONTROL OF THE VEHICLE AND A SINGLE CAR ACCIDENT INTO A GAURD RAIL. THE SECOND FAILED TIRE IS STILL AVAILABLE. ALL FIRESTONE TIRES HAVE SINCE BEEN REPLACED ON THE VEHICLE.