What brand are they? I've done a lot of searches and reading on this issue. The "horror stories" are pretty much limited to TowMax brand 15" and 16" tires. I can't find anything regarding issues with 13" or 14" TowMax tires (mine are 13" and I'm in my 3rd season with them). All other brands seem to be no better or worse than average.
Keep in mind that any tire can fail. Follow "tire best practices"; keep them cold inflated to the PSI listed on the sidewall, never exceed the speed rating listed on the sidewall (65 mph for most STs, some are higher), stay under the max weight rating listed on the sidewall.
2013 Jayco Jayfeather X20 E, 2008 GMC Sierra 1500 Crew Cab Z71 SLE