Power cut

The lights go off and stay off.

If the houses around you are still lit, check your fuse box for a switch that has tripped.

Updated

Do now

Check on

Don't

Don't: use a barbecue, camping stove, or gas or paraffin heater indoors. They give off carbon monoxide.

Don't: use candles as your main light.

Don't: go near fallen power lines. Stay well away and call 105.

Call 999 if someone is in immediate danger.

The kit for this

Sources