That is really disheartening. I think about stuff like that from time to time. Tonight, I was coming home and had a green through a fairly major intersection. I noticed that a car on the other major perpendicular street was heading into the red light on that street a little too quickly, so I slowed down ... a lot. As it turns out, that person did stop, but PAST the crosswalk, and they were seemingly too eager to make that right turn onto the street I was using. Drive defensively.
The worst I've seen was a multi-car accident while driving from the Seattle area to the Portland area on I-5 on a Friday night after work. This was about 20 miles past any metropolitan area and while traversing the forested countryside. All the traffic in both directions was crawling for half an hour to an hour up to the scene. The vehicles were all sedans, IIRC. There were no tangible expanses of metal to be seen anywhere. They all looked like they had been shredded. All sorts of emergency response vehicles were at the scene. It was gross to look at and you don't want to imagine how it played out. You just collect yourself and keep driving, as safely as you can.