Excuse my math problem :P It seems to me that these factors can make people much more concerned about a danger:

A) Few but large scale killings - eg 100 planes of 100 people each seems worse than 10,000 cars of 1 person each.

B) A single identifiable group of outsiders that can be blamed. Most people drink so drinkers aren't outsiders.

But this last factor surprisingly doesn't seem to be a worry, as evidenced by people's willingness to drive, despite the fact that it sounds like it should induce terror:

C) Random sudden death without warning.