2000 Subaru Outback tires problems

Tire seam blew out, in a perfect circumference, accompanied by profuse smoke. Extremely dangerous situation since I could not see what was happening to my car due to the smoke. I thought I blew a gasket. Brought tire to firestone dealer, where they did a soap test. No punctures were there except the complete breakdown of the seam on the outside of tire. They replaced it, however, they replaced it with anotherk wilderness tire.

Dt: the caller used spare tire and the sidewall blew out. Tire had 110 miles on it at the time. The caller was going between 60 and 65 MPH. The tire was full of black powder and the rubber was crumbling. The caller heard a rumble, and when he was trying to pull over to see what it was ,the tire blew out. Tire was only on vehicle for a week. Manufacturer told the caller to go to dealer and they would take care of the tire. Dealer would offer no help. However, manufacturer did pay for tire.