I agree with you completely, ultramarina. My son is 5 (nearly 6), and is very sensitive. He does not like anything that is very scary, and he particularly doesn't like any shows or movies where there is a character who is mean to another one (he won't watch one Team Umi Zoomi episode because there is a dump truck in it who is mean to someone). I personally love that about him; he has been described by multiple parents and teachers at his school as being a kid "who doesn't have a mean bone in his body".
My approach is to reassure him at this age that things he hears about (tornadoes, volcanic eruptions, etc) won't happen to him or anyone he knows. At this point, he just needs reassurance so he doesn't have to worry; he doesn't need the grim perspective of unvarnished truth. When he is older he will get a better sense on likelihood and probability, and we can have more elaborate discussions. Right now, his worries tend to keep him from being able to go to sleep, so we try to help him work through why those things shouldn't worry him right now (e.g. no volcanoes in Florida, etc, which can go on and on ad nauseum). My husband was the same way and has issues with anxiety and OCD; I won't be surprised if my son ends up the same.
