[jpatokal]

No, it sounds good, because it's realistic and then you can build mitigation strategies.

I was recently involved in an outage that occurred because the sama datacenter was hit by lightning three times in a row. Everything was redundant up the wazoo and handled the first two hits just fine, but by the time the power went out for the third time within N minutes, there wasn't enough juice left in some of the batteries!

Now would it be possible to build an automated system that can withstand this? Probably. But would your time & money be better spend worrying about other failure modes? Almost certainly.