Buying D or War Zone Properties

[James C.]

All,

I apologize if this is in the wrong place. 

Does anyone here invest in class D/War Zone multi unit properties? If so, what are some of the things to watch out for? How do you find competent property managers, and do you compensate them more? What about Section 8 renters? how do you deal with CAPEX/repairs when your renters are using doors to surf down fire escapes? Does the building need to be a concrete bunker? What about security? Is it ever worth trying to "clean up" a neighborhood, or just let it be what it is? I realize each location/property is different and has different challenges. I'm looking for more general D/War Zone advice.