THE AMERICAN tragedy that began on a sweltering August afternoon with an unarmed black teen named Mike Brown shot dead and left facedown on a Missouri street came to a head in the wind-whipped darkness of a November night, with the word that a grand jury declined to charge Darren Wilson, the white cop who killed him.

But the gut-wrenching national drama is hardly over.

Both before and after last night's bizarrely timed 9 p.m. Eastern-time announcement, protesters poured into the streets by the hundreds - not just in Ferguson, Mo., the once-anonymous St. Louis suburb that became a symbol of 21st century civil unrest, but on Market Street in Philadelphia and in dozens of communities from coast to coast.

Chanting "Hands up, don't shoot!" and "No justice, no peace!" the swelling crowds initially blocked traffic outside the Ferguson police station, where TV cameras showed demonstrators in down jackets hugging in the chilly night, several in tears, as the grand-jury decision was announced.

Moments later, the protests turned violent as CNN reported that demonstrators destroyed two police cars and threw rocks and bottles at officers in riot gear, amid reports of random gunfire and the looting of a liquor store and an auto-parts store. Within an hour of the ruling, the streets of the Missouri city were purple with haze from smoke bombs, St. Louis County police said in their Twitter feed that a Molotov cocktail had been hurled at officers, and at least a half-dozen major stores were in flames.

In Philadelphia, Mayor Nutter told reporters last night that he was disgusted by the legal process in Ferguson, that he still didn't understand why Wilson shot Brown multiple times and that authorities in Missouri "botched this entire tragedy so badly from start to finish."

Marchers barreled through Center City, weaving somewhat randomly - first heading west, away from City Hall, but then looping around to East Market Street, past the Gallery, attracting stares from bewildered downtown diners.

Protesters screamed "f--- the police!" at the top of their lungs, but no confrontations emerged between the crowd and the scores of Philadelphia police officers who kept pace on their bicycles. Earlier in the evening, police Chief Inspector Joe Sullivan spoke of the importance of giving the protesters space and respect, and trying to maintain a steady flow of communication with whoever was in charge of the crowd.

As of midnight, a solid sea of people had wended its way south and east of City Hall, halting at the on ramp to Interstate 95 near the base of the Benjamin Franklin Bridge. Residents and merchants on South Street gawked at the peaceful marchers.

"I think there's going to be an outpouring of anger across the country, and I'm expecting that we're going to see a lot of that in Philadelphia," said Mark Kelly Tyler, the pastor of Mother Bethel A.M.E Church. He spoke before the announcement from the sanctuary of Arch Street United Methodist Church, as pockets of police officers were already ringing City Hall, one piece of a national law-enforcement mobilization that had been building for days.

Added Tyler: "My hope is that at the end of the night, everyone will have a chance to speak their peace and get things off their chests, so we can begin to organize and really address the systemic problems."

But activists did not get what they'd initially sought during weeks of heated summer protests that were frequently met by tear gas and flash bangs: A trial where Wilson would be forced to justify firing multiple shots at the 18-year-old Brown after an Aug. 9 pedestrian stop led to an apparent struggle between the two.

Robert McCulloch, the St. Louis County prosecutor, announced the grand jury's decision not to charge Wilson in a 30-minute monologue that was remarkable for its strident and defensive tone. He lashed out at "the 24/7 news cycle and an insatiable appetite for something - for anything - to talk about" and what he called "unfounded rumors on social media" for fueling unrest in the case.

The grand jurors were "the only people who heard every witness," he said, "and every piece of evidence" in deciding that Wilson should not be charged. He added that the killing of the unarmed teen "has opened old wounds and it has given us an opportunity to address those old wounds."

"We are profoundly disappointed that the killer of our child will not face the consequence of his actions," Brown's family said in a statement after Wilson was not charged. "While we understand that many others share our pain, we ask that you channel your frustration in ways that will make a positive change. We need to work together to fix the system that allowed this to happen."

The Associated Press reported that Michael Brown's mother, Lesley McSpadden, was sitting atop a vehicle in Ferguson as she listened to McCulloch's announcement over a car radio. It said she burst into tears and began screaming before being whisked away by supporters.

President Obama, in a nationally televised statement moments after the announcement, echoed the Brown family in calling for calm and for restraint both by protesters and by law enforcement. Obama said that cops "need to work with the community - not against the community" in respecting peaceful demonstrators while weeding out those committed to violence.

But as the president spoke from the White House, TV networks showed clashes between police and protesters in the streets of Ferguson.

The announcement was not a total surprise. Prosecutor McCulloch - who has a reputation as a strong defender of law enforcement - resisted calls for a special prosecutor and made unorthodox decisions to not request a specific charge from the grand jury and to allow Wilson to testify, while testimony that supported Wilson was selectively leaked to the news media. Wilson's whereabouts remained a secret even though he got married last month and met with news anchors eager to interview the embattled officer.

Brown had just earned a high school degree and was about to start technical school when Wilson stopped him and a friend for walking down the middle of the road. Police later released a video that appeared to show Brown stealing cigars from a nearby convenience store and shoving its owner, but also provided contradictory evidence about when Wilson knew of that incident and whether that affected his conduct.

After the initial scuffle at the police car in which Wilson's gun was fired, witnesses said Brown ran more than 100 feet and was shot six times at least; several eyewitnesses said in interviews that his hands were up when the fatal shots were fired, although leaked news reports suggested that Wilson believed the youth was charging toward him.

In Philadelphia last night, protesters were disappointed at the decision but vowed to continue with protests.

"A life is lost, no matter what a prosecutor announced tonight," said Leslie MacFadyen, a South Jersey resident who founded Ferguson National Response Network, a group that organized protests in several dozen cities. "We need to end this culture of fear and suffering for all families."

At City Hall, Russell Watson, 29, was among those who grabbed the megaphone and tried to get the crowd to turn their emotions into something useful.

"I spoke from the heart," Watson, a Philly native, said afterward. "Everyone out here should be outraged, even the police officers. Especially the African-American officers - Mike Brown could be their son or daughter."

For activists, the weeks of demonstrations were what they hoped was the beginning of a national conversation about aggressive police practices in predominantly minority communities, about ongoing political and economic disparities, and social injustice. Many noted that Ferguson was a mostly minority community with a police force that is more than 90 percent white.

In an evening news conference a few hours before the announcement, Missouri Gov. Jay Nixon, who'd made the unusual move of declaring a state of emergency and summoning the National Guard a week ago, urged that "people on all sides show tolerance, mutual respect, and restraint." His words capped a remarkable buildup to the announcement in which 100 FBI agents were dispatched to Missouri, local police ordered more than $100,000 in riot gear and law-enforcement officials shared information in national conference calls.

In Philadelphia last night, a lone protester showed up at the intersection of Broad Street and Cecil B. Moore Avenue, near the Temple University campus.

Cory Hill, who lives around the corner, spent hours at the scene clutching his fluorescent green "R.I.P. Mike" sign. When he received an alert on his phone about the announcement, he described himself as "speechless."

"I'm just lost," he said. "You never know how people are going to react."