I saw a video about that shit.
Don't ask for advice on fucking reddit.
Don't let the wife sleep with the kids, after you told her you're leaving.
So many other mistakes. Of course she's the worst, but her soy

man could have prevented the deaths.
Not by staying with her, but leaving the kids at the grandparents house or something.
Which he did for a while. I don't know why he brought them back.