One person was killed and at least 15 were injured, including some children, in a shooting at the end of the parade to celebrate the Super Bowl win by the Kansas City Chiefs, sending terrified fans running for cover and marring yet another high-profile public event with gun violence.

Kansas City Police Chief Stacey Graves detailed the shooting’s toll at a news conference and said two people had been taken into custody. She said she has heard that fans may have been involved in apprehending a suspect but couldn’t immediately confirm that.

“I’m angry at what happened today. The people who came to this celebration should expect a safe environment.” Graves said. Police did not immediately release any details about the people taken into custody or about a possible motive for the shootings.

It is the latest sports celebration in the U.S. marred by gun violence, following a shooting last year in downtown Denver after the Nuggets’ winning an NBA championship that injured several people, and gunfire last year at a parking lot near the Texas Rangers’ World Series championship parade.

Social media users posted shocking video of police running through a crowded scene as people in attendance hurriedly scrambled for cover and ran away. One video showed someone apparently performing chest compressions on a shooting victim as another person, seemingly writhing in pain, lay on the ground nearby. People screamed in the background.

Another video showed two onlookers chase and tackle someone, holding that person down until two police officers arrived.

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.

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

“This is absolutely a tragedy, the likes of which we never would have expected in Kansas City, the likes of which we’ll remember for some time,” Lucas said.

Lisa Money of Kansas City, Kansas, was trying to gather some confetti near the end of the parade when she heard somebody yell, “Down, down, everybody down!”

At first Money thought somebody might be joking until she saw the SWAT team jumping over the fence.

“I can’t believe it really happened. Who in their right mind would do something like this? This is supposed to be a day of celebration for everybody in the city and the surrounding area. and then you’ve got some idiot that wants to come along and do something like this,” she said.

Kevin Sanders, 53, of Lenexa, Kansas, said he heard what sounded like firecrackers and then people running. After that initial flurry, calm returned, and he didn’t think much of it. But he said 10 minutes later, ambulances started showing up.

“It sucks that someone had to ruin the celebration, but we are in a big city,” Sanders said.

University Health spokeswoman Nancy Lewis said the hospital was treating eight gunshot victims. Two were in critical condition and six were in stable condition, she said. The hospital also was treating four people for other injuries resulting from the chaos after the shooting, Lewis said.

Lisa Augustine, spokesperson for Children’s Mercy Kansas City, said the hospital was treating 12 patients from the rally, including 11 children, some of whom suffered gunshot wounds.

St. Luke’s Hospital of Kansas City received one gunshot patient in critical condition and three walk-in patients with injuries that were not life- threatening, spokesperson Laurel Gifford said.

“When you have this many casualties, it’s going to get spread out among a lot of hospitals so that you don’t overwhelm any single ER,” she said.

Chiefs trainer Rick Burkholder said he was with coach Andy Reid and other coaches and staff members at the time of the shooting, and that the team was on buses and returning to Arrowhead Stadium.

“Praying for Kansas City,” Chiefs quarterback and Super Bowl MVP Patrick Mahomes said in a post on X, formerly known as Twitter, that also included three emojis of hands in prayer.

Missouri’s Republican Gov. Mike Parson and First Lady Teresa Parson were at the parade during the gunfire but were unhurt. “Thanks to the professionalism of our security officers and first responders, Teresa and I and our staff are safe and secure,” Parson said in a statement.

President Joe Biden has been briefed on the shooting in Kansas City and will continue to receive updates, a White House spokesperson said. White House officials have been in touch with state and local leaders, and federal law enforcement is on the scene supporting local law enforcement.

Areas that had been filled with crowds were empty after the shooting, with police and firefighters standing and talking behind an area restricted by yellow tape.

Throngs had lined the route, with fans climbing trees and street poles, or standing on rooftops for a better view. Players rolled through the crowd on double-decker buses, DJs and drummers heralding their arrival. Owner Clark Hunt was on one of those buses, holding the Lombardi Trophy.

The city and the team each chipped in around $1 million for the event commemorating Travis Kelce, Mahomes and the Chiefs becoming the first team since Tom Brady and the New England Patriots two decades ago to defend their title.

After decades without a championship, the city is gaining experience with victory parades. Five seasons ago, the Chiefs defeated the 49ers for the team’s first Super Bowl championship in 50 years. That followed the Kansas City Royals winning the World Series in 2015, the city’s first baseball championship in 30 years. That year, fans abandoned their cars on the side of the highway so they could walk to the celebration.

Then, last year, the Chiefs defeated the Philadelphia Eagles 38-35 and prophetically vowed they would be back for more.