Actually I always wondered what would happend in an All Charedi society on Shabbos
You cant shut down everything for Shabbos
You Need people to monitor the Electrical Board for the Electric Company (There ARE people who need Electricity to Live like people on ventalators and Hospitals)
You Need people to man the 911 call center (or whatever you have instead)
You need some pharmacies to be open for emergency drug supplies
You need police , fireman and EMS workers on call
etc