If an earthquake hits an area, and facilities used in accessing internet connection destroys, internet connection maybe paralized and it will be impossible to access the internet. We can't do anything about it but to wait until everything is fixed and normalized.
Even small technical faults can deteriorate the system and may force you to live in a world with no online links. This is how things operate and if the signal transmitting body is not working due to any reason, of course there is no other way but to fix it. The internet waver are not like the radio waves which can travel long boundaries.
They are limited to a given range however if you are using a SIM that has international roaming, using a network from Canada in an area hit by catastrophe in India can allow you to use internet.