Definitely scewed...
The maps account for the type of event and city size, but are scewed for few reasons.
1. Flooding and flood risk is ignored. Take the recent quake in Japan. The quake itself caused little damage and life loss as compared to the tsunami it created. The vast majority of the Katrina damage was flood realated. Someone above mentioned Sacremento which could be wiped from the map by a flood. Flooding, especially floods resulting from man-made levy/damn failure, is not easily predicted either.
2. Major cities with their vast populations are at almost no risk for tornados. The nature of how tornados work require flatter expanses of land to form and grow. Cities with highrise buildings don't allow for this just as hills, mountains, and valleys do not. So they are common in outlying areas where there is lesser populations and people are prepared for these storms. I have lived in the Mid-West my whole life and have been through a couple of tornados. That is why any house I will ever own will have a basement to hide in. And while the tornados are not "predictable" the conditions for them are so it isn't hard to know when to run for cover.
3. Event predictabilty is also ignored. This is why I think earthquakes are the most dangerous event. Earthquakes come with no warning and can hit major metropolitan areas catching people by surprise. Tornados are also not very predictable, but the conditions are and most of us in "Torndado Alley" know when to bunker down. Hurricanes to me are the least dangerous because you generally have days of advanced notice. I say this with the exception of the flooding potential brought on by the storm, but then this goes back to point 1.
