it will definitely crash down together with internet. Bitcoin solely survives thru the internet. Without internet, cryptocurrencies will have no platform for any activity since Bitcoins have no physical counterparts.
Nothing will happen to bitcoin, bitcoin will stay bitcoin even if the internet will shut down, the right question is, what would happen to us if the internet will shut down, that would be a headache since we can't access bitcoin without internet, we can't do Trading and whatever stuffs we are doing to earn cryptocurrencies(though internet shutting down seems impossible in this age).