KANSAS CITY, Mo. -- One person is dead, and 21 others were wounded by gunfire at the end of the Chiefs' Super Bowl parade Wednesday, according to authorities.
Three people have been detained and are under investigation, Kansas City Police Chief Stacey Graves said during a news conference Wednesday evening.
Of the people wounded by gunfire, eight were in immediately life-threatening condition and seven were in life-threatening condition, Kansas City Fire Chief Ross Grundyson said at the news conference.
"I'm angry at what happened today. The people who came to this celebration should expect a safe environment." Graves said.
Kansas City Mayor Quinton Lucas said all the Chiefs' players, coaches and staff were safe and accounted for, which was later confirmed by the team in a statement.
"We are truly saddened by the senseless act of violence that occurred outside Union Station at the conclusion of today's parade and rally," the team said in the statement. "Our hearts go out to the victims, their families and all of Kansas City."
The NFL said in a statement, "We are deeply saddened by the senseless shooting that occurred today near the end of the rally in Kansas City for the Chiefs. Our thoughts are with the victims and everyone affected. We are grateful for the quick and thorough response of law enforcement and emergency personnel."
Social media users posted shocking video. One user's 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 down and tackle someone, holding that person down until two police officers arrived.
Graves said police were working to determine whether one of the three people that have been detained was the person tackled in the video.
"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.
Children's Mercy Hospital told KMBC-TV that they were treating 12 patients from the rally, 11 of which were children, and nine that have gunshot wounds.
St. Luke's Hospital of Kansas City received one gunshot patient in critical condition and one walk-in patient with injuries that were not life threatening, spokesperson
Laurel Gifford said.
The University of Kansas Health System said at a news conference that they were treating eight with gunshot wounds, including two in critical condition.
Joe Sciara, a 59-year-old Kansas City native who was at the parade with his family, told ESPN's Paula Lavigne that the shooting started "immediately after the last speech" at the rally.
"I saw people running in every direction. ... From where I was standing, my initial thought, the sound was such a rapid popping sound, it sounded more to me like firecrackers than a gun. So, I wasn't initially panicked but because everybody started running, we had no choice but to start running," he said. "When I looked back, I kept looking for the shooter because I wanted to make sure we weren't running toward the shooter. I couldn't see a shooter. I saw people down, several people down, but I couldn't tell if they were shot or if they were trampled. The mass of people was hard to describe."
Missouri Gov. Mike Parson and the first lady were at the parade when shots were fired but are safe, Parson posted on X.
"State law enforcement personnel are assisting local authorities in response efforts," Parson posted. "As we wait to learn more, our hearts go out to the victims."
Multiple Chiefs players took to social media to express their concern for the victims after the shooting.
Chiefs quarterback Patrick Mahomes posted on X, "Praying for Kansas City...," also including three emojis of hands in prayer.
Chiefs linebacker Drue Tranquill posted on X, "Please join me in prayer for all the victims in this heinous act. Pray that doctors & first responders would have steady hands & that all would experience full healing."
Offensive lineman Trey Smith posted to X, "My thoughts and prayers are with everyone affected by today's incidents -- a huge thank you to the first responders who ran towards the sound of danger. You're the ones who should be celebrated today."
The shooting broke the celebratory mood on Valentine's Day as Chiefs fans marked their third Super Bowl title in five seasons.
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.
The Associated Press contributed to this report.