Some followup to some of the questions.
I did not hit the gas-------------instinct was to get it straight first.
There was no warning or any tread separation or even a little wandering before the blow-out. I didn't inspect it closely (it's now in the spare tire carrier where it will stay until next spring), but the sidewall was blown out in one area of the tire.
As for age, it sits in an enclosed shed 40+ weeks of the year out of sunlight (and with the jacks down to take the load off things). It normally gets driven a couple of times in the spring and summer and then a 6-8 week trip in the fall. If 6-7 years is the recommended age for MH's that sit outside year-around(where is that written?), shedding should add another year or two. There was also no weather cracking.
There were 48,000 miles on the tires with uniform wear (no rivering). The tread wasn't down to the wear lip between the treads, but getting close.
It has now been winterized and is ready to go back in the shed. Next spring, I will need to do some tire shopping.