I was working in Melbourne, staying near St. Kilda, and was told by some colleagues "don't go down street X at night", so I went down street X at night, had a nice meal there, walked back, no fucking worries at all.
Next morning I heard on the news that someone had been stabbed to death on that street within half an hour of my being out and about there.
The thing is, though, if you're not out causing trouble or selling drugs or buying drugs, or a member of the various competing underworlds, then you're likely to be totally fine. The stabbing was drug related.
It's a bad neighborhood if you're part of what makes it a bad neighborhood - in this case, at least.