Tire Sidewall problems of the 1997 Ford Ranger

Bf goodrich replacement tire on a 1997, Ford, Ranger with 47000 miles. While driving 55 mph left rear tire went flat due to a split around sidewall near tread. No accident, no injuries. P225/70r14 dot: befcnx71479.

Consumer has a 1997 Ford Ranger. Passenger's front tire blewout traveling at 60-65mph. Tread didn't separate, but there was hairline cracking along the sidewall. Tire blew in the center of the tread. Approximate mileage in low 60's. Orginal tires size p235/75r15 & dot# w2hl. All 4 firestone wilderness at tires experienced hairline cracking on the sidewalls at the tread line.