zd:
Actually I always wondered what would happend in an All Charedi society on Shabbos
You cant shut down everything for Shabbos…
Your question brings up a similar question in a completely Modern Orthodox community:
If people are monitoring the electrical grids for the electric company-
If people are manning the 911 call center-
If people are manning the pharmacies-
If people are manning the police, fire and EMS stations-
…
Then who’s keeping Shabbos?