Remember the Joplin, MO tornado of last year? Well, I live by there and let me tell you first off that really a basement is not all that safe either. So you think if a basement is not 100% safe, how can a mobile home be?
Last year this man's basement in Joplin collasped when his house did. Know what they found in his basement? 2 cars, 1 truck and the roof of his house, so a basement is not fully secure and safe, although you have a more chance of surviving in a basement than above ground when a tornado is approaching your area. Just last week in Kansas, my mother in law, who lives in a mobile home and has a storm shelter in her front yard, was so freaked out with the 70 mph winds that blew off some vinyl siding on her mobile home, that she didn't go to the storm shelter, she went into her shower! I couldn't believe it!!
I was like, "You have a storm shelter right in your front yard!" She was like, " I was so scared I couldn't move". Maybe your husband panicked when danger was approaching and wouldn't move or something. I have heard that some people have so much pride that they will not seek safety.
I don't know. But if I was you I would tell him the next time he doesn't move out of the mobile home, I'm gonna drag him out!
Good Luck!