BALTIMORE (CNN) -- Latest developments:
• The Baltimore Orioles game with the Chicago White Sox that was scheduled to start at 7 p.m. Tuesday has been postponed, the team announced. The decision was made after talking with Major League Baseball, state and local officials, according to the Orioles. This follows the postponement of the same two teams' game Monday.
• The Baltimore Ravens canceled their draft party scheduled for Thursday night at M&T Bank Stadium "out of respect to the curfew in Baltimore," according to the NFL team. The NFL draft is set to begin Thursday night in Chicago.
• Johns Hopkins University will not have any classes Tuesday or Tuesday night in Baltimore, the school tweeted.
Charred cars and buildings. Hospitalized police officers. Looted and damaged businesses. No school, because it might not be safe for children to go outside.
That was the stark reality Tuesday after a day and night that saw 202 arrests, 144 vehicle fires and 19 structure fires, according to city spokesman Kevin Harris.
"What happened ... destroyed so much of the progress that the people who actually live here have been working for," said Mayor Stephanie Rawlings-Blake, calling Monday "a very dark day for our city."
"What happened last night made sure that more people are struggling and that more people have needs, and those needs are going to go unmet because of what was destroyed."
At least 15 officers were wounded in the unrest, six of them seriously, the city's police commissioner said.
The tumult follows a spate of protests across the country over the deaths of black men after encounters with police: Michael Brown in Ferguson, Missouri; Eric Garner in New York; and Walter Scott in North Charleston, South Carolina. Underlying all this unrest is what Baltimore City Council Member Brandon Scott called "a long, long, longstanding issue with young African-Americans."
"We're talking about years and decades of mistrust, of misfortune, of despair that it's just coming out in anger," Scott told CNN. "No, it is not right for them to burn down their own city. But that is what's coming out of these young people."
Laquicha Harper, a 30-year-old Baltimore resident, called the violence and destruction embarrassing and "heartbreaking," saying "we owe it to ourselves to do better." She was among locals who responded Tuesday morning with brooms, not rocks, to clean up the mess left behind.
"I understand that everybody is upset, I understand that tension is brewing ... I'm here, I get it," she said. "But there are better ways that we can handle our frustration. And they can't hear us when we're behaving this way."
'They dishonored Freddie's legacy'
In Baltimore, it's supposed to be about Freddie Gray. He died on April 19, one week after being led into a Baltimore police vehicle.
His family wants justice, hoping that multiple investigations shed light on why and how he died. They want police to be transparent and be held accountable.
What they don't want, though, is violence -- certainly nothing along the lines of what happened Monday, the day of his funeral. Gray's mother, Gloria Darden, had pleaded, "I want y'all to get justice for my son, but don't do it like this here."
A lawyer for Gray's family, Mary Koch, called what Baltimore woke up to Tuesday a distraction from the family's goals of getting justice for Gray and preventing more people -- including other African-Americans -- from experiencing their grief.
"The one thing they wanted was some peace and some calm on the day that he was actually buried, and (they) asked the community to do that," Koch told CNN. "And the community didn't honor their wishes. And, in that way, they dishonored Freddie's legacy."
Riots started with 'purge' rumors
In some ways, Baltimore has been simmering since Gray died from a spinal cord injury that he suffered while in police custody. Protesters hit the streets for days, asking questions like how did Gray suffer his fatal injuries, why did it take authorities so long to get him medical help and why was he arrested in the first place.
Firm answers are still slow to come on all those fronts, though some may emerge with the anticipated Friday release of a police investigation.
Still, while there were demonstrations and arrests, what happened Monday was very different.
It started with rumors of a "purge" after school Monday starting in Baltimore's Mondawmin Mall. The rumors echoed a film about a dystopian society in which, for one day each year, all laws are suspended for one 12-hour period.
Police Commissioner Anthony Batts said authorities knew about a "large 'purge' of high school students from across the city," staging 250 to 300 police officers at the mall as a precaution.
But it wasn't enough, according to Neill Franklin, a former Maryland state police officer who has worked with Baltimore police. Franklin told CNN that law enforcement officers "were prepared physically, (but) they were overwhelmed by the number of students."
Commissioner: 'Cute to throw cinder blocks at police'
Police in riot gear took cover behind an armored vehicle as assailants -- the instigators appearing to be high school students, according to Batts -- hurled various heavy object at them.
"I think they thought it was cute to throw cinder blocks at police," the police commissioner said.
On top of that, Baltimore police warned of a "credible threat" that gangs including the Black Guerilla Family, Bloods, and Crips had agreed to team up to "'take out' law enforcement officers."
It's not known how many, if any, of the police officer's injuries could be traced to gangs.
Nor was it clear how many, if any, rioters, peaceful protesters or innocent civilians got hurt in the mayhem.
Senior center engulfed in flames
There were many other secondary casualties -- people who saw their neighborhoods torn apart, their homes and vehicles damaged, their hopes for stability and progress thwarted by the mayhem.
They were people like Cindy Oxendine, who took the streets to sweep up rocks, glass and more despite her aching back.
"It started off peaceful, and it ends up like this," Oxendine told CNN affiliate WBAL. "... I've seen stuff like this on the news in other cities, but I never thought I would see it in front of my doorstep. It's crazy."
In addition to the clashes with police came the flames, with ATF investigators joining local authorities to look into arson, a federal law enforcement source said.
The same source says that the dozens of fires that erupted around Baltimore appear to be tied to the unrest. This includes one that consumed an affordable housing center for seniors that was just months away from opening.
Pastor Donte Hickman of the Southern Baptist Church, which owns the facility, said 60 units of senior housing were lost.
"My eyes have been filled with tears," Hickman said. "Someone didn't understand that we exist in the community to help revitalize it."
State of emergency declared
Preventing more tears, more destruction and more violence was authorities' top priority Tuesday.
To this end, Rawlings-Blake, Baltimore's mayor, took steps as well by imposing a mandatory daily curfew from 10 p.m. to 5 a.m. This is for everyone and in addition to a 9 p.m. for children under 14, while youths ages 14 to 16 have to be inside by 10 p.m. on school nights.
And Maryland Gov. Larry Hogan declared a state of emergency and activated the National Guard, with 500 members on the ground Tuesday morning, hundreds more on their way and up to 5,000 ready to answer the call.
They'll join Baltimore police and up to 5,000 law enforcement officials that will be requested from around the mid-Atlantic region to help prevent more violence, said Col. William Pallozzi of the Maryland State Police.
Maryland State Police ordered an additional 40 troopers to Baltimore to join 42 troopers sent there Monday afternoon. Since last Thursday, more than 280 state troopers have provided assistance in Baltimore.
Meanwhile, some residents are trying to step up. They include people who came out to clean up like Harper and 15-year-old Sulaiman Abdul-Aziz, who said he saw some of the mayhem.
"I felt disappointed," Abdul-Aziz said, "because a lot of that could have been avoided if people would have started thinking before they would have done all that stuff."
CNN's Athena Jones reported from Baltimore, and CNN's Greg Botelho and Holly Yan reported and wrote this report from Atlanta. CNN's Evan Perez, Jason Hanna, Dana Ford and Ben Brumfield contributed to this report.