There is alot that needs to be taken into account when comparing all of those weather phenomena. When it comes to phenomena such as a winter storm or hurricane there is typically tremendous lead time to start preparations. Like Scott said, when it comes to winter and people driving like idiots...well that's something to factor too. Phenomena such as thunderstorms, flooding, and tornadoes the lead time isn't as great (and for obvious reasons).
Of the deaths (relating to say lightning, tornadoes, wind damage) the question becomes what kind of actions did the individual take or what kind of guidance was provided by group leaders in settings involving large groups of people? For the most part, a majority of weather-related deaths can be avoided. Of course there are exceptions.
anyways...that is a sad and truly heart-breaking story.