I fail to see any crime being broken.
I'm recently a father and understand the safety precautions one takes for his family and how protective I am, but what exactly did this man do wrong?
Should he have had his kids buckled? Yes... Did he intend to kill his family? No I can remember when I would ride with my parents when I was younger, I didn't wear a safety belt. Should they be thrown in prison for it? If I were to ACCIDENTALLY (remember that its an accident) die from a car accident when my parents were driving, should they currently be serving a life sentence in prison? Does that make them less quality of people than they are today?
Lets be a little realistic... You can't throw everyone in jail just because something bad happens. Its tragic, it sucks, and the pain and suffering that family has to go through GREATLY outweighs any superficial pain and suffering our legal system could put them through.