As if we needed one, the news out of Ferguson, Missouri, is yet another reminder of the divide between black and white Americans, one that is having serious consequences.
Ferguson deserves the focus it's getting, not only because the killing of Michael Brown was such a tragedy but also because the early police reaction to the protests was such an outrage.
And despite the violence that has erupted during the protests, there've been two positive developments: widespread criticism of Ferguson police officers' response and media coverage of the police use of military equipment.
The news about Ferguson will die down eventually, though. And another big story will grab our attention.
And that'll be yet another tragedy. Because the Ferguson developments have roots. Those roots exist throughout the country. They exist in Rochester. They existed in Rochester in 1964, and they're every bit as alive now.
All last month - with speeches, articles, radio and television programs, exhibits - Rochester observed the 50th anniversary of the '64 riots. But you have to wonder: During all of that solemn introspection, did we learn anything? Anything that will result in significant change?
There was plenty to learn. But it wouldn't be a surprise if the only role the anniversary played was to refresh the memories of people who already knew about the riots and to provide a local-history lesson for those who didn't.
In Ferguson, black community leaders have tried to insure that the protests are peaceful, but there's been violence anyway, as there was in the Rochester riots. And Ferguson is giving communities like Rochester a warning.
This community won't come to grips with its own racial and economic divide - and the warning from Ferguson - overnight. But at the least, we can begin to recognize that the roots of the protesters' explosion are the same as the roots of Rochester's 1964 riots.
And there are some things we should do right now.
First, we can become informed about the militarization of our own police departments - what equipment they have, the policies for its use, and the circumstances under which it can be used.
The Rochester Police Department has one MRAP vehicle - a mine-resistant, ambush-protected armored vehicle - which it acquired in June of this year, the RPD says. And it has the SWAT equipment that you would expect a police department to have: night goggles, masks and clothing to protect officers from chemical and biological hazard, that kind of thing.
There are indeed occasions when police officers might need to have that equipment. But the public has a right to know what the equipment is - and the policies and justification for using it.
The RPD says the MRAP vehicle would be used in situations involving armed, barricaded suspects; negotiation with armed suspects; chemical or biological attacks; natural emergencies; and similar events. It could also be used during natural disasters because of its size, weight, and four-wheel drive features.
The key, then, is for police departments to have policies, training, and oversight that insures that the equipment is used under the right circumstances, and not during events such as peaceful protests.
Second, we need to thoroughly assess the criminal justice system: drug policies, stop-and-frisk policies, loitering policies, all the things that humiliate, dehumanize, and criminalize so many young black youths.
And third, we need to get serious, at last, about addressing the roots of the problem that are at the heart of all this - in Ferguson, in Rochester, throughout the country.
"Make no mistake," Tufts University Professor Peniel E. Joseph wrote on The Root earlier this week. "Brown's killing is not the root cause of Ferguson's violence. It's merely the spark that triggered it. Poverty, segregation, unemployment, and a climate of anti-black racism haunt tiny Ferguson and the wider St. Louis metropolitan area. Riots, Dr. King reminded us, are 'the language of the unheard' and oppressed."
The 1964 riots shocked Rochester. Leaders of the white community hadn't seen them coming, couldn't understand why they had happened, and didn't see that they bore any responsibility, for the cause or for the solution.
Fifty years later, some things have gotten better. But the poverty, segregation, unemployment, and racism remain. In fact, they have grown.
In a recent New York Times column, Charles Blow quoted Langston Hughes: "What happens to a dream deferred?"
"Today," wrote Blow, "I must ask: What happens when one desists from dreaming, when the very exercise feels futile?"
Rochester, like Ferguson, has plenty of alienated people for whom dreaming seems futile. But too many of us, like the Rochesterians of 1964, don't see them.
And Ferguson seems far away.