Total disaster, never happens in real world, not virtual one. Except for all the times when 'real world' currencies undergo devaluations, revaluations, forced exchanges, just plain old inflation, all the things that lead to currencies collapsing. I mean name me a paper currency that lasted longer than 80 years on this planet without a major restructuring, without collapsing?
The Swiss Franc? Unless you count things like exchange rate manipulation by the central bank, but that isn't really a collapse.
Those who can, do; those who can't, simulate.