Detroit certainly has its crime problems, but it has had a bad press. It isn't THE most crime ridden city. Its homicide rate is very high, but on the other hand in its suburbs, the rate is below the national average.
It is the motor city of note, so perhaps it's not surprising the motor crime is horrendous here. Why not use the excellent public transport to get there, and to get around? Avoid out-of-town nightspots if you can, and don't walk around alone.