At this moment, the one thing that would cause national catastrophe is World War III. Unfortunately, it is a real possibility because the U.S. Government is pushing with all its might to achieve it. But, if it does, there will be no place to go anyway, so why go? No matter where radiation gets us, we shall die, so why not die at home?

Perhaps it’s just me and my American delusions, but I hardly see WWIII as the possibility some do.
But I do see an attack on the infrastructure as a reality. Be it domestic or foreign terrorists, it’s the worst thing that could be done short of all out war, which no one wants. Not the Russians, the Chinese, or the North Koreans.
Why? Because everybody loses with the World War.

However a low tech attack on the grid, done simultaneously across the nation would shut everything down and for longer than many might believe. Sure some “critical” services would go on thanks to personal generators and such, but hardly for the time frame needed to make the repairs.

Planning for your personal worst, not some imagined worst, is the best plan.
Be it long term unemployment, fire or another catastrophe, reality is the best thing to work with and look at.
And with proper planning, you are set up for the unusual happenings most of the time.

We may not agree all the time, I dare say that it’s more the philosophy/reasoning that we disagree with rather than the practices.