Tire Sidewall problems of the 2000 Ford Explorer Sport

Driving on an interstate highway in louisiana, driving about 55 mph, changed lanes and had blowout on the driver rear tire. I was driving a Ford explorer. The blowout looked to have been caused on the sidewall, at a point where the sidewall meets the steel belts on the driving surface of the tire. There are no obvious road damage to the tire. The local goodyear rep said that they have no recall on the tire and they have never seen this damage before and would not warranty the tire. The original tires were firestone, but were changed out by the Ford company to goodyear because of the firestone recall. The tires had about 29,000 miles on them and the air pressure was checked 2 days before during an oil change. The tire is goodyear, wrangler rt/s m+s p235/75r15 ser# 274220-grf-70mmwvs it also has the numbers e13 0293095 stamped on them.