KANSAS CITY, Mo. — The mass shooting that unfolded amid throngs of people at the Kansas City Chiefs’ Super Bowl celebration appeared to stem from a dispute between several people, authorities said Thursday.

Police Chief Stacey Graves said that the 22 people injured in the shooting ranged between the ages of 8 and 47 years old, half of whom were under the age of 16. A mother of two was also killed.

Three people were detained — including two juveniles — but no charges have been filed yet, Graves said. Police are calling for witnesses, people with cellphone footage and victims of the violence to call a dedicated hotline.

"We are working to determine the involvement of others. And it should be noted we have recovered several firearms. This incident is still a very active investigation,” Graves said at a news conference.

The shooting outside Union Station occurred despite the presence of more than 800 police officers who were in the building and area, including on top of nearby structures, said Mayor Quinton Lucas, who attended with his wife and mother and ran for safety when the shots rang out. But he doesn't expect to cancel the upcoming St. Patrick’s Day parade.

“We have parades all the time. I don’t think they’ll end. Certainly we recognized the public safety challenges and issues that relate to them,” Lucas said.

Throngs had lined the parade route before the shooting, with fans climbing trees and street poles or standing on rooftops for a better view. Players rolled through the crowd on double-decker buses, as DJs and drummers heralded their arrival.

The police chief said 1 million people likely attended the parade, which occurred in a city with a population of about 470,000 people and a metropolitan area of about 2 million, but stressed that the violence was wrought by just a handful of people.

“The law enforcement response was exemplary. Those in attendance also responded," Graves added. “They helped one another and even physically stop a person who was believed to be involved in the incident.”

Meanwhile, police are still asking witnesses to come forward. Many described a sense of confusion that rippled through the crowd.

The rally had just ended and music was still blaring when the shots erupted. Many people initially thought they were hearing fireworks. But then chaos ensued. Some in the crowd hit the ground while others leapt over barriers and sprinted from the scene, some carrying children in their arms.

The crowd was so massive that normalcy returned quickly, with some fans unsure what had happened. But then ambulances arrived and officers rushed in with guns drawn. Some of the less seriously injured were driven away on golf carts.

The stunned crowd — some in tears — slowly gathered their belongings, trying to figure out how to get home. Strangers comforted each other as police put up crime scene tape in an area where moments early it had been a joyous celebration.

Hank Hunter, a sophomore at a Kansas high school, said he heard shots in the distance while watching the rally with a friend. Initially, they didn’t know what it was, but then “like a chain reaction” people started hitting the ground.

They ran to jump over a barricade and his friend slammed his head into the concrete, Hunter said. A security guard ushered his friend into Union Station, which was closed to the general public, as the players and coaches prepared to leave on buses. There, coach Andy Reid consoled his friend and "just tried to comfort him and calm him down.”

Social media users posted shocking video of police running through Wednesday's crowded scene. One video showed someone apparently performing chest compressions on a victim as another person, seemingly writhing in pain, lay on the ground nearby. People screamed in the background.

Another video showed two people chase and tackle a person, holding them down until two police officers arrived. In an interview Thursday with ABC's “Good Morning America,” Trey Filter of Wichita, Kansas, said he saw someone being chased and took action.

“I couldn’t see much. I heard, ‘Get 'em!’ I saw a flash next to me. And I remember I jumped and remember thinking, ‘I hope this is the fool they were talking about,'" he said. “They started yelling that, ‘There’s a gun! There’s a gun!’"

Filter said he and another man kept the person pinned down until officers arrived. "I remember the officers pulling my feet off of him and at that point I was just looking for my wife and kids,” he said.

It was not immediately clear if the person he held down was involved in the shooting, but Filter's wife, Casey, saw a gun nearby and picked it up.

The woman killed in the shooting was identified by radio station KKFI-FM as Lisa Lopez-Galvan, host of “Taste of Tejano."

Lopez-Galvan, whose DJ name was “Lisa G,” was an extrovert and devoted mother from a prominent Latino family in the area, said Rosa Izurieta and Martha Ramirez, two childhood friends who worked with her at a staffing company.

“She's the type of person who would jump in front of a bullet for anybody — that would be Lisa,” Izurieta said.

Kansas City has long struggled with gun violence, and in 2020 it was among nine cities targeted by the U.S. Justice Department in an effort to crack down on violent crime. In 2023, the city matched a record with 182 homicides, most of which involved guns.

Lucas has joined with mayors across the country in calling for new laws to reduce gun violence, including mandating universal background checks.

“We did everything to make this event as safe as possible,” Lucas, a Democrat, said in an interview on KMBC-TV Thursday. "But as long as we have fools who will commit these types of acts, as long as we have their access to firearms with this level of capacity, then we may see incidents like this one.”

University Health spokesperson Leslie Carto said two of the eight gunshot victims brought to the hospital are still in critical condition. One is in stable condition. The other five have been discharged. The hospital also treated four people from the rally who had nongunshot injuries. Three of those patients were discharged, Carto said.

Stephanie Meyer, chief nursing officer for Children’s Mercy Kansas City, said it was treating 12 patients from the rally, including 11 children between the ages of 6 and 15, nine of whom suffered gunshot wounds. All were expected to recover, she said.

When asked about the condition of the children, Meyer responded: “Fear. The one word I would use to describe what we saw and how they came to us was fear.”

St. Luke’s Hospital spokesperson Emily Hohenberg said one gunshot victim at the hospital remains in critical condition. Four people who suffered injuries while fleeing the aftermath of the shooting were treated and released.