There is a city full of innocents. Men, women, children; civilians. But danger is coming, and because those civilians live in the city each and every one of them is grave danger. Maybe it's a Big Bad hoping to sack or massacre the city, maybe it's an impending natural disaster. Either way, it's too late to prevent what's coming and if people stay there they will die.

So they evacuate. They leave the city behind in order to escape with their lives. The local military or government might be organizing the evacuation (which would count as a