Q: Who's to blame?

A: The Fractional Reserve System

Q: Can this happen to any bank?

A: Technically, yes. In reality, no. The very biggest banks will get saved by the central banks. Unless central banks are keen on justifying global civil wars.

Q: Why can even five-year-olds comprehend that the fractional reserve system is a fundamentally brain-dead idea?

A: Because through this system, money is either destroyed slowly (by lowering interest rates & QE; to maintain increasing systemic leverage), or it's destroyed fast (by raising interest rates & QT; triggering defaults and risking cross-industry debt spirals).