That's the tough and hard thing about using a currency that is based and used for the internet and the only chance for it to survive would be the internet being online and running, though to do this day I don't think we could ever go through something like that and no government in the world would never allow such a catastrophe to happen in the least, the internet is going to live on forever at this point.
So, this is never going to happen bud and Bitcoin will live on forever.
Internet now is much needed in our society, everything now is on internet, businesses and markets were on the flow of internet or system So when its gone if ever its not bitcoin alone who'll get affected also the society.