Nobody will. In fact, most car fatalities that are caused by humans involve zero criminal charges for anybody involved. In America, everybody from the courts to the media to society at large is primed to think of car accidents as normal. If you want to murder somebody in the middle of town in broad daylight, you can actually get away with it, as long as you do it with your car.
Well with an autonomous system, you can actually audit what the machine was "thinking" and how it came to think that way, so you actually can distinguish between an accident and criminal negligence better than a he-said-she-said situation with humans
When a piece of construction equipment falls over and kills someone, the person or company who owns the equipment is liable. I image it would be the same thing here.
Sometimes that person then counter-sues the manufacturer of the equipment if they think it was faulty. I image that would also happen here if there were personal ownership of self driving cars.
