Police are still searching for the shooter or shooters, while the lives of the victims have changed dramatically.
One man spent a night in the hospital after being shot in the leg. He says he knows most if not all of the people who were wounded, including the youngest victim, a 3-year-old boy who was shot in face.
With the aid of a cane, he returned to where it happened, the basketball courts at Cornell Square Park in the city's Back of the Yards neighborhood.
"This park would usually be full of kids. A deserted park," he said. "People are scared every day."
It was a different scene Thursday night when the park became a crime scene.
This 37-year-old father of two, who asked not to be identified, was seated courtside with several others.
The bullets, he says, came from the other side of the fence.
"Everybody stumbling over each other. Thought I got knee'd in the thigh. Looked down. Bullet hole," he said.
He'd been shot in the leg, but stayed on his feet, rushing to aid of his relative, 3-year-old Deonta Howard, who'd been shot in the head.
Moments earlier, Deonta had been petting a friend's dog.
"His face is just… It just hurts me to see he was like that," he said. "He was a strong kid. He didn't cry. I guess he probably was in shock."
Deonta would survive his wounds and so would the 12 others who were shot, including one victim who still has the bullet lodged in his leg.
"You have no heart at all if you can do something like that," he said. "Women and children? C'mon. That's not right."
Even before this park was sprayed with bullets, neighborhood residents, he says, had a nickname for the city.
"They called Chicago 'Chi-raq,' like Iraq," he said. "It's into us to change. It's into the community, people getting involved, everybody coming together because this is going to be an ongoing thing."
That victim says a few inches here or there and that bullet may have done more than just wound him.
That victim is calling on the shooter or shooters to turn themselves in. Police say they're questioning people but have no one in custody.