The answer is yes, but this is so for every country. The US is generally safe, but there are areas of every city you will want to avoid. There are very dangerous areas, worse if you are of a certain race. I would never go to Hilltop in Tacoma, Washington. And, that isn't even the worst. Obviously, places of extreme poverty in large cities will have danger. But it is unlikely you would stumble into them, since they are not tourist destinations.