3 days is enough for the council/utilities to get organised and sort shit out or come up with a plan.
Local scenarios have been:
flat fire that shorted the electrics in the rest of the building.
Flooding closes the road to the supermarket
Storms, heatwaves, snow.
Water off (took over 24 hours for them to find and fix it)
Banking issues for specific banks
Power cuts (Spain and Portugal for example)
Wildfires (evacuation or stay in due to smoke)
Illness, accident or disability.
Bereavement
Factory fires (etc)
Unexploded WW2 bombs (Coventry and South coast this year)
Cyber attacks are likely. Several companies have been affected.
Flu pandemic. Or another illness possibly
Terrorism (Gloucestershire eg)
Flight disruption due to air traffic control or volcanoes again.
Strikes.
Diesel shortages due to Trump attacking Iran, affecting supply chains, shipping. Also suddenly having to go the long way round.
Landslips blocking roads , long way round to the supermarket, lorries can't deliver easily. (Lots of rain can trigger this. )
Car break down, etc.
Depends where you live. We're unlikely to flood but getting up hill in the snow even in town can be tricky. We're more likely to have our electric back quickly, but more likely to be less adapted to that being in a flat with only electric heating. Shops are in walking distance but riots, crime, and terrorism are more likely. (And fucking idiots with fireworks. Tend not to go out after dark if possible as they get launched from street corners or horizontally straight down the street. Or off balconies or at our windows, the bastards )