Problem with this scenario is that there would be mass panic, looting, & ultimately violence. Hospitals with patients that are directly reliant completely reliant on vital machinery in order to stay alive would be the first victims once the back up generators (gas) run out. If all electrical equipment ceases to function, then there will be a number of air traffic tragedies that would inevitably lead to mass casualties.
A more dire situation would be an airburst generating a strong EMP wave, hitting a country or the Nantucket series premise: Electricity & all combustible energy based things cease to function permanently. So much worse than just electricity, no guns, cars, missiles, etc.
Actually made you think when you see people having to relearn agricultural skills, archery, forging, etc.