Later, something even more chilling beamed out of my hometown and across the Internet: Police officers responded to a "disturbance" at a pool party in a wealthy part of town. According to some of the teens involved, a squabble broke out when several (white) adults began complaining that many (black and white) teens had arrived at the pool. A white woman slapped a black girl, one witness said, and a larger brawl involving hair-pulling broke out.

When they arrived, police officers told several black boys at the scene to sit on the ground. One white officer, Eric Casebolt, drew a gun on a couple of unarmed black boys. When 15-year-old Dajerria Becton, who is also black, began walking away, Casebolt threw her to the ground and pinned her there, his knees pressed against the small of her back.

Before this month, the last time McKinney made major news was in the fall, when it was named the best place to live in America by Money magazine. It's among the fastest-growing cities in the country, and lately big companies have infused the region with thousands of jobs in fields such as energy and aviation. Starting this year, Money wrote, every high-school freshman in McKinney would be issued a Macbook Air to aid in his or her studies.

"Underlying McKinney’s homey Southern charm is a thoroughly modern city," the Money story gushed.

Southern charm is charming, of course, until it isn't.

As my colleague Yoni Appelbaum described yesterday, the wealthier, whiter part of McKinney, to the west of Highway 75, sits in stark contrast to the older, poorer, and more racially diverse section to the east. Kids who live in west-side developments like Craig Ranch have gated pools and playgrounds nearby, not to mention parents who will drive them to activities. They can easily escape the stifling summer heat or find rides to their after-school jobs.

Kids who live on the east side might be cooped up inside aging houses. Or worse yet, they might be invited to a pool party on the west side, only to be driven away by white neighbors and viciously attacked by the authorities. Perhaps even more depressingly, at least one black woman who witnessed the argument at the pool said most of the black attendees at the pool party were residents of Craig Ranch. If that's true, it suggests that the white Craig Ranchers were engaged in a kind of racism so retrograde that it would make even their great-grandparents shudder.

McKinney is indeed a great place to live for many people. It's safe, has great schools, and even the most determined hooligan would find little opportunity to make trouble. (For a while, the town was completely dry—a quirk that was a constant source of agony for my Russian father but was, in all honesty, likely a net benefit for most parents of teens.)

Despite its rapid expansion, McKinney is still a southern town, with all the attendant politeness and comfort, yes, but also some of the more illiberal elements of southern culture. There were only a handful of mixed-race relationships in my high school, and there were no openly gay students. Before I went away to college, I had only ever met one other Jewish person my age.