I can see Web 3 being useful after the initial shock to fund-raise, and to facilitate local peer-to-peer transactions if the banking system has fallen over.

But until we've got mass adoption to match or exceed Facebook and Twitter, those legacy Web 2 social media platforms will probably be the best way to reconnect people, to find out who survived and who didn't.

In terms of communication in the immediate aftermath, it still fails for the same reason legacy systems fail; no power and no mobile phone masts.

The best solution I've seen so far was after the Maui disaster, where enough local people had Starlink to get satellite internet access and used solar panels and battery swapping to keep enough mobile phones going. It seems the local government wanted to impose centralised disaster response and stop people communicating independently, and were told where to go....