Thanks for the info- sounds like a classic cascading-blowout case.
Of course, I'm sure the guy at Walmart was right about those tires- after fourteen years and who knows how many miles, what trailer tire WOULDN'T be "ready to go"? I s'pose you don't know the brand now that they're all gone. You don't mention the your trailer model year- could the tires have been original to the trailer?
p.s.
I feel your pain about "not enough spares"- had that happen one year with the TOW VEHICLE! Out in the middle of nowhere, two flats in a row. Had to get the whole shootin' match towed forty miles to town just to get the flats repaired.