Tire Sidewall problems of the 1997 Dodge Grand Caravan

I own 8 mx4 michelin tires I rotate and use 4 in the winter and four in the summer. While driving at 70 mph I experienced a catastrophic blow-out on my front passenger side tire im a professional driver and have logged over 1. 5 million miles in commercial and personal vehicles and I utilize the smith system . The road was clear with little traffic and no road hazards present. Two weeks later on the highway at 55 mph. Another massive blow-out left rear both times large holes in the sidewalls one tier manufactured in 2000 the other in 1999 miles on both tires 17k tiers inspected and confirmed blowout originated from the inside . Similar occurrences have been reported. My remaining six tires have been inspected for side wall damage or unusual wear and none found vehicle has been serviced and no defects found.

We keep the tires at the vehicle manufacturer's recommended 35 psi. The ambient temperature was between 75 and 80 deg. We were traveling about 30 mph and the vehicle was not heavily loaded. We did not hit any object in the road nor any pothole. There was no warning such as vibration in the rear or bouncing of the wheel. The sidewall of the tire ruptured suddenly with a rip in the sidewall almost from where it meets the rim, straight across the sidewall radially and slightly into the tread. If this had happened at highway speeds instead of in a 30 mph zone, this incident could have caused a serious accident because of the suddenness of the tire failure.

Front goodyear eagle LS tires experienced blowouts, first incident was a sidewall failure, second was tread separation, tire size p215/65r16.