Police are working to figure out who opened fire and why after they say one person was killed and more than 20 wounded at the end of the Kansas City Chiefs’ Super Bowl victory rally Wednesday, sending fans in red jerseys running for cover as law enforcement swarmed the area, confetti still blowing in the wind.

Children were among those shot, authorities said, as an estimated 1 million people gathered Wednesday just steps from Union Station in downtown Kansas City, Missouri, for the parade and rally to mark the Chiefs’ repeat championship win, with players still on the stage when the chaos erupted.

Three people were detained and an unspecified number of guns recovered as officers converged, said Kansas City Police Chief Stacey Graves. No charges had been announced by Wednesday night and no suspects had been named.

“We do not have a motive, but we are asking those who may potentially have any kind of information, a witness or video, to contact police,” the chief said at a Wednesday news conference.

Authorities are still working to determine the exact number of victims, which Graves on Wednesday evening put at 22 shot, including the person who died. Four hospitals together received 30 patients – 19 with gunshot wounds – from the shooting, their staffs told CNN. Children’s Mercy Hospital received 11 children between ages 6 and 15 – nine who’d been shot – from the scene, hospital spokesperson Lisa Augustine said.

The shooting was the second in a year at a major US sports title celebration, after two people were wounded in June as Denver fans left a parade for the NBA’s Nuggets. The attack in Kansas City marked yet another place Americans saw a sense of safety punctured by gun violence, following shootings at churches, schools, grocery stores and outlet malls. And it was at least the 48th mass shooting in the United States so far this year, according to the Gun Violence Archive, which like CNN counts those in which four or more are shot, not including a perpetrator.

“I am angry at what happened today,” the Kansas City police chief said Wednesday. “The people who came to this celebration should expect a safe environment.”

Police now are collecting physical and digital evidence, and interviewing witnesses and victims, Graves said. The FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives both responded to Kansas City to help police, a Justice Department spokesperson said.

Radio DJ Lisa Lopez-Galvan died after getting shot at the rally, her employer KKFI 90.1 FM said. Police have not identified the person who died in the shooting.

“We are absolutely devastated at the loss of such an amazing person who gave so much to KKFI and the KC community,” station spokesperson Kelly Dougherty said in an email to CNN.

Lopez-Galvan “leaves behind an incredible legacy,” said Manny Abarca, a Jackson County, Missouri, legislator who was at the parade with his daughter. He knew Lopez-Galvan, describing her as a member of a “very large family of civic leaders” actively involved with the city’s Latino community.

“She was the light at every party. She was often times the voluntary DJ when everyone needed one for a community event,” he told “CNN This Morning.”

“This is absolutely a tragedy the likes of which we would have never expected in Kansas City and the likes of which we will remember for some time,” Kansas City Mayor Quinton Lucas said at a Wednesday news conference.

Members of Lopez-Galvan’s family are among those injured during the shooting, according to a Facebook post by the mayor of Lee’s Summit, a suburb about 20 miles southeast of Kansas City.

Lopez-Galvan’s brother is Lee’s Summit Mayor Pro Tem Beto Lopez, Mayor Bill Baird wrote, noting two of Lopez’s nieces and a nephew were injured.

“This is truly heartbreaking and an absolute tragedy,” Baird said, asking his community to pray for the family.

Police detain person tackled by fans

Paul Contreras was at the event with his daughters when people started running.

He saw someone moving “in the opposite direction” and heard someone yell to stop him, he told CNN’s Erin Burnett on Wednesday. Contreras hit the person from behind and tackled him, knocking a gun to the ground, he said. Two other attendees then helped hold the person down.

“You don’t think about it. It’s just a reaction,” Contreras said.

Police arrived at the scene and handcuffed the person pinned to the ground, video shows.

“He was fighting the whole time,” Contreras told CNN. “And we were fighting him to keep him down.”

It’s unclear if the person tackled by Contreras was among those police said they detained. “We are working to determine if one of the three are the one that was in (a) video where fans assisted police,” Graves told reporters.

Shooting survivor Jacob Gooch Sr., who was shot in the ankle, told CBS on Thursday he overheard an altercation prior to the shooting, in which a girl told someone else, “Don’t do it, not here, this is stupid.”

Gooch – who said his wife and son were also shot – told “CBS Mornings” his wife and daughter then saw someone draw a gun.

“My daughter said that some lady was, like, holding him back,” Gooch said, “and people had started backing up and then he pulled it out and just started shooting and spinning in a circle.”

The FBI has set up a tip website and invited the public to submit videos that capture the shooting or suspects trying to flee the scene.

Investigators will try to use that visual evidence to link anyone already in custody to the shooting, said CNN Senior Law Enforcement Analyst Andrew McCabe, the former deputy director of the FBI.

While having several people already detained is a “great start,” McCabe said, “it’s a long way from having a witness who can actually tell you that the person who you have in custody is also a person who was firing a weapon.”

‘I felt like I was going to die’

The celebration started with Chiefs players, including Super Bowl MVP Patrick Mahomes, on double-decker buses, waving to fans as they rolled through the city. Some players left their rides to walk the parade route, high-fiving fans along the way.

A victory rally following the parade featured several players toasting the team’s connection with the city.

The event wrapped up. Then, gunshots rang out.

Manny Abarca and his 5-year-old daughter had left the main stage area when they heard screams and saw a flood of people running toward them, he told CNN’s Laura Coates.

“People were saying, ‘Guns, police, run,’” said Abarca, a former treasurer of the Kansas City Public School Board.

He picked up his daughter and sheltered in a nearby restaurant with Kansas City Chiefs players, owners, family members and head coach Andy Reid, he said.

Abarca’s young daughter went into “protocol mode,” telling her father, “This is like training,” he said.

Madison Anderes, 24, was at the event with her brother and mother when they heard what they at first thought were fireworks, she told CNN.

“He’s got a gun! He’s got a gun!” someone then yelled before a second round of pops went off, this time significantly louder. “That’s when all chaos broke out.”

Anderes was knocked down on the ground as everyone started running.

“I felt like I was going to die, I felt like a sitting duck and I was going to get shot,” she said.

Anderes then got up and ran with her brother and mother to a storefront, where about 10 others were huddling, she said. At that point, she said she saw law enforcement enter the scene.

Lucas, the mayor, was at Union Station when the shooting erupted.

“I was inside of Union Station, we heard something, a number of us start running and I see a stream of officers going the exact other direction in with guns drawn, ready to address danger,” Lucas said. “People … responded absolutely immediately. But I wish that we lived in a world where they wouldn’t have to do that.”

Hundreds of officers were at the event, including atop buildings – yet people were shot “in a matter of moments,” the mayor said.

Chiefs players helped calm scared children

Kansas City Chiefs players, coaches and staff are all accounted for and safe, the organization said, adding in a statement, “We are truly saddened by the senseless act of violence that occurred outside of Union Station at the conclusion of today’s parade and rally.”

Trey Smith, a Chiefs offensive lineman, told ABC on Thursday he took cover with bystanders as shots rang out Wednesday, sheltering in a closet with a group of people, including a child.

“Right before I run in there, there’s like a little kid in front of me so I just grabbed him – just yanked him – was telling him ‘You’re hopping in here with me, buddy,’” Smith said. “I don’t know how many people that were in the closet.”

Long snapper James Winchester, was “very instrumental in helping keep people calm,” Smith said. Once the group was cleared to leave the closet, Smith saw a small boy who he described as “hysterical,” and handed the boy a wrestling championship belt he’d been carrying as a prop during the parade.

“Hey buddy, you’re the champion. No one’s gonna hurt you,” Smith said he told the boy.

Star tight end Travis Kelce expressed anguish over the shooting: “I am heartbroken over the tragedy that took place today. My heart is with all who came out to celebrate with us and have been affected. KC, you mean the world to me,” he posted on X.

President Joe Biden in a statement said the Super Bowl win should have been a joyous occasion.

“For this joy to be turned to tragedy today in Kansas City cuts deep in the American soul. Today’s events should move us, shock us, shame us into acting. What are we waiting for? What else do we need to see? How many more families need to be torn apart?”