Kansas City Chiefs parade mass shooting stemmed from dispute, 2 juveniles detained

The mass shooting that erupted at the end of the Chiefs' Super Bowl celebration in Kansas City, Missouri, appeared to stem from a dispute, according to police.

The shooting, in which one person was killed and 22 were hurt, unfolded outside Union Station as Chiefs fans were leaving a parade and rally on Wednesday. More than 800 law enforcement officers were on duty in the area, as 1 million paradegoers were expected to attend the celebration, according to Kansas City Mayor Quinton Lucas.

Two juvenile suspects are currently detained and charges have not yet been filed, according to Kansas City police. The department is working with juvenile prosecutors "to review investigative findings and determine applicable charges," a police spokesperson confirmed to ABC News Thursday evening.

A third juvenile who had been detained in connection with the shooting was determined not to be involved and is no longer in custody, according to the police spokesperson.

Several guns were recovered, police said.

At least half of the victims are under the age of 16, Kansas City Police Chief Stacey Graves said Thursday.

Fire officials said the victims included eight critically hurt and seven seriously hurt.

Children's Mercy Hospital said it received 11 children, ranging in age from 6 to 15. Hospital officials did not specify if the 6-year-old was wounded by gunfire or injured in the resulting chaos.

Nine of the children taken to Mercy Hospital had been shot, officials said. Three remained at the hospital on Thursday and all of the victims are expected to recover, officials said.

University Health said it received eight gunshot patients, including two who remain in critical condition Thursday.

A University Health doctor and the Kansas City Fire Department's medical director were both at the parade, and they were able to triage patients and get the sickest people to the hospital first, University Health trauma surgeon Dr. Dustin Neel said.

The first victim to arrive at the hospital is one of the patients in critical condition, Neel said. Within five minutes of arriving at the hospital he was taken to the operating room where doctors were able to stabilize him, Neel said. The injuries he sustained are 90% lethal, and had he not arrived when he did, he might not have survived, Neel said.

The second patient in critical condition also underwent surgery on Wednesday, and doctors are hopeful she'll be upgraded to stable condition in the next few days, Neel said.

The police chief commended the paradegoers who "helped one another and even physically stopped a person who was believed to be involved in the incident."

She called the law enforcement response "exemplary."

"I'm angered by what occurred ... but I am also thankful for the response," Graves told reporters.

Killed in the shooting was Lisa Lopez-Galvan, a DJ at local radio station KKFI 90.1 FM.

"This senseless act has taken a beautiful person from her family and this KC Community," the radio station said in a statement Wednesday.

The 44-year-old leaves behind her husband and two young children.

"We woke up this morning excited and the last thing we ever expected was to have a tragedy in our family," her brother, Beto Lopez, told ABC News.

All Chiefs players, coaches and staff were confirmed safe.

So far this year, there have been at least 48 mass shootings in the United States, with 81 killed and 165 wounded, according to the Gun Violence Archive.

ABC News' Victoria Arancio, Youri Benadjaoud, Alexandra Faul and Pierre Thomas contributed to this report.