I'm not sure as neither time it's happened I've been around, but basically the bead slips off which deflates the tyre and seems to ruin the bead for future use.
Is the bead actually snapping?
I'm not really sure - whatever is happening to it the bead won't mount again properly.
@Howard started
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I'm not sure as neither time it's happened I've been around, but basically the bead slips off which deflates the tyre and seems to ruin the bead for future use.