It's okay to feel bad about someone's death without acting like they personally knew the guy. Maybe someone is to blame, depends what angle to look at it from. I wouldn't wholely blame it on his parent, but I do think that they should have picked up on something this bad (autism), being his parents and all, but then we don't know their relation, actions or awareness. Maybe they where in denial and denied anything wrong with the boy.
This is going to sound, and will be, very harsh with current standards but naturally if something living has a great enough defficiency then that living thing would die off so it doesn't pass on to offspring and so a healthy chain in is kept in the race. So with that and what I said in the first paragraph, maybe the end result would have been the same disaster.