Tire Sidewall problems of the 2005 Toyota 4Runner

Driving west on interstate 8 at appx 77 mph; 60 miles east of yuma when right rear tire sidewall blew out. Vehicle swerved severely but was manageable. Roadway was dry, 90 degrees f, no debris, tire still in owners possession.

I had just begun acceleration from a stop sign when I heard a noise and the 4runner became loose on the back left. It was making a noise like I had never heard before. I was able to pull to the side of the road after about 100 yards. On inspection, the sidewall had blown in a straight line from about 2 inches from the rim toward the tread creating a nearly straight gash that I could stick my entire hand into. I took the vehicle to gosch Toyota (the dealer who sold me the vehicle 8 months ago). They said they do not take care of warranty issues with tires. I took the vehicle to America's tire and they attempted to contact bridegestone for warranty authorization. Bridgestone was not open. The service manager agreed to try to call them on Wednesday.