This is a different topic--I'll allow it as a new thread.
I'm thinking the most likely disasters would be either nuclear or biological, e.g. if the smallpox virus got 'accidentally' released. I think my generation is the last to have been vaccinated against it. If Ebola ever went pandemic, we'd be screwed. The mortality rate for it is horrendous, and anyone who did survive would require huge amounts of medical care. The system would be completely overwhelmed.