How to prevent it from ever happening again

To prevent it from happening again.  They say this after every screwup.  There is a simple answer.  Find who caused it and fire him/her.  Publically.  That will teach 'em.  We haven't fired anyone for causing great depression 2.0.  We haven't fired anyone over Benghazi.  We haven't fired anyone at FBI for failing to inform Cambridge police that Tamerlan Tsarnaev was fingered by the Russians as a terrorist.  We haven't fired anyone at IRS for targeting the Tea Party.  We haven't fired anyone at BATFE for giving guns to Mexican drug runners.
   They never learn unless they know something bad will happen to them for being stuck on stupid.