It happens. I have had two blowouts, although they were due to my own stupidity - I didn’t bother checking the date code and relied on the fact that the tread was in good shape. Blew one out on the way to camp, and the 2nd on the way back. Put bias ply tires on it - was all they had on short notice. Year later saw a bubble on the sidewall, dumped the bias ply and went back to radials, which is what I should have done to begin with. Tires for trailers, including pups, are not super high quality. They also don’t seem to last as long in the sun as they used to as well. I think I am going to plan on replacing them every 3 years or so. Our troop trailer has also had regular blowouts as well, and they have had Goodyears on the rims when that happened.