I think there is technically a fault line in Louisiana, but there is essentially no risk of an earthquake that would cause real damage. But there is likely more chance of that happening than an avalanche.
Certainly there is a higher risk of floods in the Appalachia's but I suspect many people that live there were not really aware of it until now and it's probably not something that insurance agents were pushing in the area. So, I have a lot of sympathy for those who do not have it in that area.
Although I will say that lots of people talked smack about people should not live in flood zones and areas prone to natural disasters post Katrina. It took hurricanes and blizzards in New York for people to start realizing that natural disasters and floods can happen most places.