A few years ago, I was returning by car to Washington from Baltimore when I took a wrong turn and got lost. Suddenly I found myself in a street where gangs of black youths were hanging around on street corners outside houses with boarded up windows.
For a moment I felt as though I was in the world inhabited by the criminals and drug addicts of the TV series The Wire.
I was able to escape from the neighbourhood but they were not.
US President Barack Obama said on Wednesday that the nation has some soul-searching to do about allowing impoverished members of the black community to be "stripped of opportunity". He recognised that "this is not new: it's been going on for decades".
The rioting that shook Baltimore, a city of 630,000 with a two-thirds black population, was not as widespread as suggested by some commentators who recalled the 1968 paroxysm of violence following the Memphis shooting of Martin Luther King.