Water cut off for whatever reason (natural disaster, fire, terrorist attack)
Food supply chain cut off for whatever reason (natural disaster, extreme weather, pandemic, fire, social unrest...).
Electricity cut off for whatever reason etc. Etc.
I say fire because my building had its water supply cut for 48 hours without warning due to a fire.
Where i live now all the supermarkets in a certain part of the island were burnt down. People had to drive over an hour to another supermarket. At a time when there was social unrest everywhere and strikes so the other supermarkets didnt have much food...