I've thought about this many times in the past. The truth of the matter is, if someone intentionally decides to take you out (and this goes for general life as well as cycling) they will. While I don't go out riding expecting to be killed everytime I go out, I'm sure the people working in the WTC on Sept 11 expected to come home as well.

We're all gonna die sooner or later anyway (I expect skin cancer to be what eventually gets me), and as far as I am concerned, if one can't do the things that they want to do, it might as well be sooner.

My point? Basically take all the precautions that can reduce your risks by all means, but don't let risks stop you from living your life.