For the past several weeks, my mother who is 90 and experiencing dementia, has been convinced that our entire town is burning down. She's not in a panic about it. She acts much more matter of fact, but every car she sees is "leaving town", she asks me if I will rebuild, what the animals will do, how bodies will be identified, etc. we try to distract but she persists. What should we do? How do we handle this when she brings it up? She doesn't remember of course if we tell her all is fine. Help?