It's funny - my car has a back up camera and I cannot stand it. The side mirrors also point down automatically when you put the car in reverse. I still think I can see more the old fashioned way, even though I have to crouch down to see out my side view mirrors. As someone said above, before you have kids (or have some close calls with crazy things) you think it can never happen to you, but unfortunately, it can. All you can do is be hyper-vigilant about where your kids are, concentrate on your driving only, and always move really slowly.
Edit - it says he was moving his truck forward. It was probably a big truck and she was a small kid he couldn't see. How awful and how do you ever get over something like that?