Tire Tread/belt problems of the 1999 Cadillac Deville

My wife was traveling northbound on interstate 5 pass buttonwillow when the car began to vibrate and the driver side rear tire came apart. Some of the tread remained on what was left of the tire damaged the quarter panel, rear lower bumper and the rear door. The result was tire failure, the tread separated from the tire. A California highway patrolman stop to give assistance by calling aaa to have our car piggybacked to a big-o dealer to replace the failed tire. I purchased two new tires to be mounted in rear of the car. I've kept the old tire so that I may submit a claim to the tire manufacturer. Giving proof of product failure as well as the damage produced by the faulty tire.