Areas with a lot of HUD owned/foreclosures

I have been looking in the Saint Louis area for single family/multi-family housing. When I search HUD listings, A lot of the listings are in a specific area of town. What can this possibly forecast or mean? Is this an area that you should stay away? It this area so bad economically that people in the area can't afford houses? some of the houses are halfway decent, for example, they aren't boarded up 120 year old houses. I would probably be buying single family homes and renting them out or flipping. I know it would be hard to flip a house in a distressed area, but what about renting? What should I be concerned with or consider? To my knowledge, these areas are not war zones.