St. Louis doesn’t riot.

That has long been part of the city’s lore. During the 1960s civil rights era, this city along the Mississippi River stayed calm — even as Baltimore, Chicago, Detroit and Washington all burned. St. Louis was in their league back then. The nation’s 10th largest city. A sizable black population. And after Martin Luther King Jr. was assassinated in 1968, tens of thousands of people marched through the city streets. But St. Louis suffered no widespread violence.

It was one of those hard-to-explain moments. St. Louis doesn’t riot.

And then, Sunday night, it did.

Riots and vandalism broke out in the St. Louis suburb of Ferguson. An 18-year-old black man named Michael Brown was fatally shot by police there. Brown was unarmed. Events leading up to the shooting were unclear. Police and the FBI have promised to investigate. But a day after Brown died, violence erupted. Stores were looted. A gas station was torched. Shots were fired at police.

Maybe it was how police reacted to what initially was a peaceful memorial service for Brown. Maybe it was the echoes of Trayvon Martin, the Florida teen gunned down by a neighborhood watch volunteer. Maybe the crowd sensed police weren’t taking their concerns seriously.

It’s still unclear why, this time, tensions boiled over. But to many people, it had little to do with this town. The violent reaction grew from something larger, something tougher to pin down.

Ask people who live in Ferguson where they’re from, and most likely they’ll say St. Louis. It’s a quirk of the region. People identify with the St. Louis metro area. Ferguson, a city of 21,000 residents, is a place distinct from St. Louis city, which is different from Affton or Clayton or Ballwin. But these are mostly neighborhood distinctions. The residents all live in the same St. Louis County, which is packed with 91 different municipalities. Some have quaint downtowns. Others have just 12 residents. But at the center of all of them is St. Louis city.

What happened in Ferguson was a regional reaction. The crowds that gathered in Ferguson — both peaceful protesters and those looking for trouble — came from Ferguson, yes, but also Berkeley, University City, Jennings and St. Louis.

Just look at Antonio French.

He spent most of Sunday taking photos and shooting videos as a memorial turned into an angry mob. He was widely interviewed Monday by media nationwide. But he’s not from Ferguson. He’s a St. Louis alderman. For years he has complained about St. Louis police and how crime is handled in his predominantly black neighborhood.

“This isn’t unique to Ferguson,” French said by phone, as he stood on a street in Ferguson on Monday watching riot police march in a line toward protesters.

He added: “This is no different than if it happened in Dellwood, Jennings or St. Louis. This has really been bubbling up for a long time.”

This is about police brutality, he said. Others agreed.

“There’s a lot of angry folk. There’s a lot of people who want to make sure they’re heard,” said John Gaskin III, who lives in Florissant, another St. Louis County suburb, and who is a national youth board member of the NAACP. “This isn’t a St. Louis problem. It’s a national problem.”

Tensions between police and African American teens run deep, said Rod Brunson, professor at Rutgers University. He has studied the issue in St. Louis. “The dynamics play out on the street everyday.”

But Ferguson erupted. “And I don’t know what made it rise to this kind of level,” Brunson said.

Ferguson is about two-thirds black, one-third white. Its poverty rate is about double Missouri’s average. The town has its struggles. But Ferguson is also home to the world headquarters of Emerson Electronics, a $24 billion company with 132,000 employees spread across the globe. Thousands of people work just outside Ferguson at Express Scripts, the pharmacy benefits manager with $100 billion in annual revenues that is based in the St. Louis area.

“Ferguson would not be the first place I’d predict to have this incident or this response,” said Rick Rosenfeld, a criminology professor at the University of Missouri — St. Louis, located just a few miles from Ferguson.

Rosenfeld grew up in St. Louis city. He remembers well the region’s reputation for not rioting. In 1967, after summertime riots in cities such as Newark and Milwaukee, a young Rosenfeld ran into Dick Gregory, the activist and comic who hailed from St. Louis. He asked Gregory why their shared hometown hadn’t angrily risen up.

“The shade trees,” Gregory told him, smiling.

Gregory was joking. But his response also carried a kernel of truth. People in St. Louis were not immune to the injustices and anger of the civil rights movement. But something about that place didn’t lead its residents to lash out in anger. Not back then.

St. Louis still has its shade trees. So does Ferguson.

But you can’t say they don’t riot there anymore.