Turned out one of our tenants had burned their apartment down- total loss of property, was fortunate in that it was largely contained to one apartment(cigarette in the kitchen garbage can, then out to dinner, those fools.)

If you find the source of the fire then you'll know if it's fault wiring or a cigarette butt, or ?? 

They have been paying on time since I bought the property and have been good tenants; however, they both have cats and dogs, are smokers (outside), and the amount they are paying is ~$200 below market for unit A and ~$100 below market for unit B.

Wondering how about the smelling issue from a smoker next door?

The walls are yellow with cigarette smoke.

It would be like trying to get car insurance on a totalled car, or trying to get health insurance as a smoker AFTER you've been diagnosed with lung cancer (in a world without ACA). 

It will also create a lingering burning metal smell in the garage...do you allow cigarette smoking in the garage?

She was a very heavy smoker and I wanted the building smoke-free, so I got her to move anyway. 

This is especially helpful if you're renting to college students and you're wanting to know if they'll be throwing huge parties at your property, smoking cigarettes/marijuana in your house, or if they're secretly hiding the fact that they have a pet.

Although I don't think "weed smoker" is a protected group.