What factors affect hazmat fires? They're driving me crazy. I only have 4 high density industry buildings, and I've gotten a hazmat fire every day for the last week. Is this normal? I really don't feel like upgrading to a large fire station just for the hazmat trucks when I'm having no other problems with fires.   Edit: Just got another, that's more fires than days now. Also, it was one out of only two high density buildings, since one was rebuilding from the last hazmat fire and the other was rebuilding from not having a place to ship freight (despite the empty trade port just down the street).