As suggested by others, Alateen would be a wonderful support for them. If they like to read, there are books on dealing with alcoholism/addiction in families for teens.
My DS06 keeps begging for me to let daddy to come home. I tell him kindly but firmly that it is not going to happen. When he asks why, I tell him his daddy made a decision and I made a decision based on that. I am trying to do what is best for our family.