Rim? Axel? Bearing?

So yesterday I blew a tire, today put a new one on, blew it, same side drivers side rear. I looked under the truck in the well etc can't see anything rubbing. Soi what could blow a brand new tire that fast?

Were they Firestone/Bridgestone tires?

Brand new? Defect, if there's no mechanical object obstructing it.

Yes Bridge stone why?

If you had no issue prior to the 1st tire failure,makes me think while a tire flaw is possible could be your rim is out of round.Did you drive far,or high speed when 1st failure occurred then stop.I would def inspect the rim itself for cracks or burrs and maybe go as far as swapping front to the rear and get a new tire and see if this isolates the problem.I do not know what else to suggest beyond the general things.If the rim hit the ground hard could have damaged it or may have had a crack in it already and it just rehappened if that is a good description.

Because I had the same thing happen to me with Firestones. The spare let go less than 30 miles after putting it on. They beat the hell out of the right front fender on that car.
They make crap tires!
It was no surprise to me, a few years ago, when Ford had issues with Firestone/Bridgestone tires.