*OBVIOUSLY* the bank failed because of the bank run. What the hell does that have to do with the pertinent question of: was it rational to withdraw? Those that panicked first won. Those that didn't lost.
A bank run is a self fulfilling prophecy driven by irrational fear. It is, by definition, irrational. It also doesn’t happen much any more because most banks aren’t susceptible to them (ie. have 90%+ deposits uninsured).
