How do I mitigate fire hazards?

[AthenaRoberts]

I've no idea how to keep things from burning down and having fire departments around doesn't seem to help and neither does calling them.  It's common for me to lose several buildings at once when there is a fire.  With crime, I've noticed adding lights will lower the crime rate of an area.  For some reason, I"m not sure why, dehumidifiers always attract crime in this game and they are the most likely to burn down.  They've burned down so often that I've concluded maybe I have too many of them. So, when they burn down I don't replace them.  However, I always replace water treatment plants when they burn down.  Since I can reduce crime by adding street lights, how do I mitigate fire hazards?

Also there seem to be way to many fires in this game.  I live in hot and dry Phoenix, Arizona and even during the summer we don't have as many files as a get playing this game.  They are rare enough that it's newsworthy when it happens.

Are the fires ever caused by arson in this game or is it just chance?

Mainly though, I'd like to learn how I can reduce fire hazards.