NEW YORK (CBSNewYork) — The search is on for suspects after a deadly shooting on a Brooklyn playground.

It happened around 6:30 p.m. Thursday at the Bushwick Playground on Knickerbocker Avenue just steps away from where children were playing soccer.

The kids were in the middle of practice when they were startled by gunshots.

“I was practicing, and then I heard six shots,” one boy said. “I saw people running from the basketball court towards the field. Then my coach told us to run towards our parents and then we ran and we just saw a kid running and he fell down in the field and he was like, bleeding.”

“We thought it was like fireworks,” said another girl. “But it wasn’t. It was guns.”

Police say a group of men were fighting at the playground when a gunman opened fire, killing a 21-year-old man with a shot to his back and sending two other 20-year-old men to the hospital. One was shot in the back and elbow and another was grazed in the arm.

A mother too fearful to show her face says she was outside the park when the shots rang out.

“Once I saw the kids run out, I knew it was real,” she said.

In that moment, all she could think about was her 1-year-old. It still gets her choked up.

“I thought my daughter was in the park with my mom,” she said. “My niece was in the park, it was terrifying the scene was scary — me hearing it, I heard three. I was like yeah, it’s shots.”

Despite the park being packed with children, none were hurt. But many walked away stunned.

“I was really scared,” the boy said. “I thought they were going to shoot some of my teammates on my soccer team.”

There were cop cars and caution tape as investigators were still on the scene the next day. People walking by like Kathleen Li were in disbelief.

“We’re supposed to come to play this morning,” she said. “they love this playground, it’s so sad.”

“It’s definitely alarming, but it’s good to see the police coverage here,” said neighbor Joe Dell’Olio. “That they react quickly and then they stayed here the whole night.”

One neighbor says police often patrol the playground. While investigators continue to search for suspects, they say they’re not ruling out anything, including the possibility it could be gang-related, CBS2’s Jenna DeAngelis reported.

It’s not clear when the park will reopen. The investigation is ongoing.