Generally, people (authorities, policemen, etc) don't get fired if they failed to prevent a disaster.
They get fired if they break rules, fail to obey standard operating procedure, do not fill tick marks correctly on a paper.
They work in a system, and the system has responsibility, not individual people who work for it -- unless they neglect or break rules and procedures.
It's like the spy agencies and law enforcement are always highly competent and can never do any wrong.