You are still falling into the same trap. cost of preventing low probability events in the future >> cost of preventing events in hindsight The problem is th

You are still falling into the same trap. cost of preventing low probability events in the future >> cost of preventing events in hindsight The problem is that you do not know which events will occur, so you will inevitably spend not only on implementing that $300000 upgrade on one plant which will need it, but on many $500000 upgrades on many plants (most of which will never be necessary or related to tsunamis). The cost/benefit ratio of preventing low probability events in the future should be studied, and only after looking at such studies can we decide whether any one change should be made. For example, the US government rejects any highway improvement which costs more than $3MM per life saved, as there are many lower-cost measures that save lives, and spending on less cost-effective measures is "statistical murder".