Automatic Transmission problems of the 2001 Mercedes Benz ML320

I was driving a mcercedes-benz Ml320 on August 02, 2011. The car engine suddenly and completely shut down while I was driving. I got stuck on the inner lane of homestead rd, cupertino, CA. Fortunately I was not on a highway, otherwise, I don't know what would happen to me. I got my car towed to the mercedes service. I was told that the crank sensor did not function properly. This costs me almost my life and $500. I think it's very dangerous to passengers if a car completely shut down while driving. Mercedes-benz should have done a better job to prevent this from happening. To my point of view, this is a design flaw. I want to share this experience to all drivers with the same model and have them watch out the same situation may happen.