@Jim K.I don't know much about ABCD etc. but I know age should not determine anything or else every downtown would be rated as a D or F. 

@Linda Lovely and these are not in d or f areas.

It's not a D or R issue, it's a HUMAN issue and an AMERICAN issue. 

As long as they are not creating a living hazard (the slopy house is not a hazard) such as breaking plumbing, dor causing structural damage, I would let it go until they were ready to move out.If you rent to families with young children, this is to be expected, it comes with the territory.

As others have mentioned, this is why location is the #1 rule of real estate...you can do a million things to improve a property, but you can't do much to improve a neighborhood.Misery loves company, and it might make you feel a bit better to know that this type of scenario is somewhat common--so here's a recent thread of another investor experiencing similar problems (I'd suggest reading, since there are some solid recommendations):  https://www.biggerpockets.com/...Investors (esp. inexperienced investors) are often lured into buying properties in  D & F neighborhoods because on paper, these properties have the best cashflow (and new investors are often most focused on cashflow)...but, of course, the hassle of owning in a D or F neighborhood is often not worth any amount of cashflow.

This is most likely D or F class. 

We also call them "D" OR "F" neighborhoods. 

If you are in a C to D, or focusing on very low cost product in general, it is always the lower income demographics that are hit hardest with slow downs, and you will have trouble renting/selling. 

In that area couple years ago a man get shot right next to his home - and again, this is C+ area, not D or F.Anything can happen any time and better be ready than sorry later.I don’t carry my gun around but I do have it in my car and my house as well.

If you are purchasing in a D or low C neighborhood I would recommend Heart and Home.