Preparing for armageddon are we???
The biggest threat to human race and this world is Human race itself...
Perhaps if we had put aside our differences and overcame the insatiable greed, there may be no need for places like these...

In case of a natural event, I doubt even the securest vaults like these can survive...
Consider the case of Fukushima Nuclear Plant, all the safety measures and redundancies were top notch but in the end everything proved insufficient in countering the forces of nature.