Protestors in 120 towns and cities across America began to gather hours before the decision of the Ferguson grand jury was announced.  When it became known that Officer Darren Wilson would not be indicted, the protestors began to march.

Almost all the protests were peaceful.  Many protestors blocked traffic and lay down in the streets, but there were few arrests and no serious altercations, except in Ferguson itself and Oakland, California.

Ferguson exploded.

At least 13 people were injured – two with gunshot wounds – and 61 arrested during the riot following the grand jury decision.  Ten businesses were destroyed by fire, and most of the stores on West Florissant Street were looted.

This wasn't a few malcontents.  Police say "hundreds" of people were involved in the riot.

What I've seen tonight is probably much worse than the worst night we ever had in August, and that's truly unfortunate,” he said.

He said that there was basically “nothing left” along West Florissant between Solway Avenue and Chambers Road. “Frankly, I'm heartbroken about that," he said.

Missouri Highway Patrol Captain Ron Johnson said, “We talked about peaceful protest, and that did not happen tonight. We definitely have done something here that's going to impact our community for a long time...that's not how we create change.”

Belmar said that officers did deploy tear gas near West Florissant and Chambers roads and a highway patrol lieutenant was hit by a glass bottle. He said as far as he knew police did not fire shots but there was plenty of gunfire in the area.  He said he personally heard at least 150 shots.

He said he and Johnson drove around earlier and “got lit up,” and he was surprised they were not hit. Commanding officers were hesitant to leave officers at road blockades because of so much gunfire in those particular areas, he said.

They reported one shooting in the 9100 block of Halls Ferry Road and a report of one near the McDonald's on West Florissant Avenue.

They reported 29 arrests in and around Ferguson. They seized one handgun, he said. Two St. Louis County Police cars were torched, he said.

"Change is created through our voice, not the destruction of our community,” said Johnson.

Belmar said he didn't think the late-in-the-day timing of the announcement was a factor in the violence. He said he didn't get any advance notice of what the jury's decision would be and that he didn't expect it because it would be inappropriate under the grand jury system.

“I don't think we were underprepared,” he said.

He and Johnson spent many hours meeting with protesters and clergy in recent weeks, he said. “"We not only were engaged, we did everything we could to prevent this."

He said he expected more National Guard troops in the near future and changes in “operation procedures.”

Shortly after 2 a.m., at least five busloads of National Guard troops pulled up along South Florissant Road in the old town area of Ferguson.

Meanwhile, at least a dozen cars were on fire at an Auto By Credit dealership in Delwood at about 2 a.m. Tuesday. Just north of the dealership, a Conoco service station convenience store was destroyed by fire.

Elsewhere, in Boston, New York, Chicago, Los Angeles, and other big cities, the protests were loud but peaceful.  Protestors were allowed to block traffic on major thoroughfares, although CNN reports that efforts to block a freeway in Los Angeles were thwarted by police.

The story was different in Oakland:

Oakland police are compiling totals for arrests and property damage, hours after protesters marched through the streets of downtown and onto Interstate 580 Monday evening.

The demonstrators, most angry with a decision by a St. Louis County grand jury not to indict Officer Darren Wilson in the shooting death of unarmed teenager Michael Brown, started congregating shortly before prosecutors announced the decision at 6:00 p.m. Monday, Bay Area time.

Pictures from our helicopter partners at ABC7News showed hundreds of people crowding city streets in downtown Oakland for the demonstration following the decision.

Police asked for mutual aid from Alameda County Sheriff’s deputies and other local law enforcement agencies to help contain the protests.

Authorities shut down the on and off-ramps for Interstate 580 at Grand because of the protest activity. Later protesters entered the freeway and were walking among stopped traffic near Lakeshore for more than an hour.

More demonstrations are being organized today, so we'll see if the protestors can remain peaceful.