Thanks for all the replys. 02 American Eagle. Spartan chassis,no chaffing or dry rot or over inflating. Failure was at the top edge where it starts to turn down. At the rim would be a good description. Another interesting thing was it was mfg by Firestone as someone else posted. I'm replacing the right side as a precaution an that will give me a spare. It still appears to be somewhat rare to have one rupture given the number in service. I have owned this coach for over 10 years, do all maint myself. This was my first breakdown in over 80k so I feel Somewhat fortunate. Thanks again