CHICAGO (CBS) — It’s the Monday story everyone fears will become a reality, and sadly, yet again, we are forced to tell you about an incredibly violent weekend in Chicago.

The numbers this past July 4th holiday weekend are tragic – 79 people were shot in Chicago and 15 were killed. Two of those who died are under the age of 18; one of them was just 7.

As CBS 2’s Suzanne Le Mignot reported, police Supt. David Brown said Monday that violent offenders, out of jail on electronic monitoring, are responsible for the recent crime in the city – though he was asked for specific examples and did not give any.

Natalia Wallace was gunned down at 7:02 p.m. Saturday while playing in her grandmother’s front yard in the South Austin neighborhood.

The 7-year-old loved math and art. She was shot in the head on the 100 block of North Latrobe Avenue.

At the time, the first-grader was visiting her grandmother for a 4th of July party.

“Put the guns down! Put the guns down! We talk about Black Lives Matter, but at the end of the day, we’re killing each other off, we’re killing our babies,” said Natalia’s aunt, Natalie Wallace.

Twelve people under the age of 18 were shot this past holiday weekend in Chicago. Natalia was one of two young people killed.

Vernado Jones, 14, was also killed. He lost his life along with three others in a mass shooting around 11:30 p.m. Saturday at 61st and Carpenter streets in Englewood.

A total of eight people were shot in that incident. A 30-year-old man identified as Ernest Franklin was also among those killed; the other two victims who died have not been identified.

“We cannot allow this to be normalized in this city,” Supt. Brown said. “We cannot get used to hearing about children being gunned down in Chicago every weekend.”

Brown blames the weekend violence on what he calls “the revolving door” of the criminal justice system.

“We must keep violent offenders in jail longer. We must revamp the electronic monitoring program,” Brown said, echoing comments he has made following other recent violent weekends. “It’s not working.”

Mayor Lori Lightfoot spoke to the gunmen, who shot directly into crowds and claimed young lives.

“I sincerely pray on behalf of a grieving city that you are able to recognize the consequences of what you have done, the souls you have ruptured, and I pray that you find the purpose that is obviously lacking in your lives,” Mayor Lightfoot said.

Police announced late Monday afternoon that they will announce charges against a suspect at 5:45 p.m. in the shooting that killed Natalia Wallace. No one was in custody late Monday in the shooting that killed Vernado Jones in Englewood.