Do Not Panic! Keep Calm! Rather you are the Man or the woman in charge of the family, your children will be looking to you to get them through this disaster that has occurred. If you panic and run around like a chicken with it's head cut off, or start to freak out, then you will be causing panic and stress to them.
They will also be burden with the fact that the one person in their life who they are now turning to, has absolutely no clue what to do. It was the same for me when I was in the US Army and in command of troops in the field during combat. The young privates were looking to me for leadership. A leader must know exactly what he or she is doing at all times, or at least be convincing enough to make everyone believe he or she does.
Your job is to keep everyone else together and confident during this time. You have no time for bitching and complaining or any attitude that is non-constructive. Assure your family, "We are going to get through this, I know exactly what I am doing". A positive outlook is step one. Step two is beginning immediately to set about taking necessary action . There is no time for anything else. Get your shit together and keep it together. Get in your mind right now, you are in for some rough times but you will get through it.