[jfk13]

Isn't hindsight great? I suspect the people who designed Chernobyl thought they were being smart and careful at the time.

You can be as smart and careful as you like, and still get bitten by something you had no idea was a possibility. If you're building a wind turbine, there's likely to be a reasonable limit to how catastrophic that totally unanticipated problem might be. If you're building a nuclear plant, the stakes are a lot higher.