A close friend of mine recently told me he was filing for divorce. I've known him and his wife for decades, so I'm concerned for them both.
thats horrible, divorce is the last result. 
Yes. Unfortunately, they have kids as well. 
are the kids old enough to understand whats going on?
Yes. They're in their early teens, or near it. 
i guess thats a positive. they can understand that their life will be somewhat different