I think in a situation like this in most parts of America you'd see neighborhood watch organizations on steroids. Basically everyone with a sense of morals and/or a family they care about is going to band together block by block and lock it down that night. Empty stores and businesses make far, far easier targets for mayhem if people want to steal or burn stuff, and other roving gangs or isolated houses likely make easier targets if they want to kill. The main thing to be scared of would be an out of control fire forcing you to evacuate your neighborhood and go out into the jungle so to speak. But that's what volunteer fire brigades are for.