It is hard to predict , but I believe every disaster has two stages. First is shock, disbelieve and total disorder. That could last days,wks or even months. That where everybody is for himself or the immediate group.You do not trust anybody at this time and guns are VERY IMPORTANT. After thousands maybe millions of people die , things start settling down and new era starts.Your food storage is running out . That when survival skills comes in. The knowledge of basic life comes to use. Groups will start to form and real life starts.
Henry