The number of gunshot victims rose to 23, and their ages ranged from 8 to 47, police said in a briefing the day after the shooting. The death toll remained at one victim, identified as a beloved local radio personality.
Two juveniles and an adult were being held as suspects in the shooting, Police Chief Stacey Graves said at a press conference.
The violence erupted as "a dispute between several people" and that there was no connection to terrorism or extremism.
"We have all intentions of presenting charges," Graves said of the three suspects in custody. Their identities were not disclosed.
In addition to the woman who was killed, at least 22 others suffered gunshot wounds on Wednesday outside the city's landmark Union Station, authorities said. At least nine children were among those hit by bullets.
Children's Mercy Hospital said it had treated nine kids who had been shot, and on Thursday said "all of the victims we saw are expected to recover." The hospital also treated two other kids injured but not shot at the rally, along with an adult.
Thousands of fans had gathered with the Kansas City Chiefs to celebrate the team's NFL championship triumph over the San Francisco 49ers.
The bloodshed came at the end of the rally following a parade, and it turned the festive occasion into a scene of panic. Throngs of attendees scrambled for cover at the sound of rapid-fire gunshots.
The Jackson County prosecutor Jean Peters Baker, who will decide on filing criminal charges, wrote on social media on Thursday that "I will use every tool at my disposal under Missouri law that allows me to address this tragedy."
Baker's office said by phone that charges could come as early as Thursday afternoon, but provided no more details.
The shooting marks the latest, high-profile outburst of gun violence, which has been erupting with increasing frequency in schools, supermarkets, nightclubs and other public settings.
"This is an all-too-real American problem," Kansas City Mayor Quinton Lucas said in an interview with KMBC TV on Thursday. "But so long as we have fools who will commit these types of acts, as long as we have their access to firearms at this level of capacity ... we may see incidents like this one."
Fifteen victims suffered life-threatening wounds, Fire Department Chief Ross Grundyson said at a late afternoon news conference.
"Fortunately, there has been no reported change in status of our victims," Lucas said on Thursday.
None of the football team, their coaches or other staff attending the rally was wounded, the Chiefs said.
CIRCUMSTANCES REMAIN MURKY
Graves appealed to anyone who had information about the shooting or video that might help shed light on what transpired to share it with police.
Graves said she was aware of a video purporting to show fans subduing a suspect, and that investigators were reviewing the footage to determine if the individual was one of the people taken into police custody.
Parade attendee Paul Contreras told local television station KETV he was one of the fans who helped tackle the man, and saw him drop a gun when he was knocked down.
"The whole time he's fighting to get up and run away," Paul said, adding police arrived within moments. "We're fighting each other, you know. We're fighting to keep him down and he's fighting to get up."
The barrage of gunshots happened near a garage west of the station, whose front entrance was the backdrop to the stage for the victory rally, according to police and local media.
Union Station, a 109-year-old Beaux Arts building that once served as a major US rail hub for passenger and freight traffic, is home to a museum and visiting attractions today, and is a terminal for Amtrak passenger service.
The Super Bowl celebration featured Chiefs tight end Travis Kelce on stage with quarterback Patrick Mahomes and other teammates, but Kelce's pop superstar girlfriend, Taylor Swift, was back on tour in Australia at the time.
"I am heartbroken over the tragedy that took place today," Kelce posted on X late on Wednesday night. "My heart is with all who came out to celebrate with us and have been affected. KC, you mean the world to me."
The governors of Missouri and Kansas were among the dignitaries present at the event but they, too, were unhurt.
The shooting came three days after the Chiefs defeated the 49ers in overtime to win the Super Bowl, 25-22, marking their fourth National Football League championship.
On June 17th, 1933, Union Station was the site of an outdoor shootout and murder of four law enforcement officers and a criminal fugitive in a notorious incident known as the Kansas City Massacre.
Wednesday's violence took place on the sixth anniversary of one of the most notorious mass shootings in recent US history, when 17 people were killed and 17 more were injured at Marjory Stoneman Douglas High School in Parkland, Florida. The shooter in that incident, a former student who was 19 at the time, pleaded guilty and was sentenced to life in prison.
