Scenario is you wake up one morning and no one is there, no wife, no parents living above the basement, no flatmate (whatever the situation).
There are no bodies lying in the street, no wreckage of cars etc, everyone is just gone.
TV is out etc. You have no idea what has happened, you have no idea if there is anyone around in the world, but after a comprehensive search there is no one in the neighbourhood.
Neighbourhood pets are gone, but wildlife is still about.
What would you do?
Once I determined there was no one else, I'd find the tallest structure I could and jump.