1:51 PM PT -- The Kansas City Police Dept. Chief just said in a meeting with media members that "upwards of 10 to 15" people were injured by gunfire ... with one deceased. She added that she did not believe any of the victims were children.

K.C.'s Mayor, meanwhile, said all of the Chiefs' players, coaches and staffers are accounted for and safe.

As far as a potential motive for the shooting, the chief said that's still unclear -- as an investigation remains ongoing. Two suspects, however, are in custody ... she said.

1:22 PM PT -- Law enforcement says one person died in the shooting -- while nine others were injured.

1:19 PM PT -- Disturbing and graphic video has emerged from the scene ... showing multiple people needing medical attention -- while blood is clearly on the ground nearby.

The Chiefs' Super Bowl parade has just taken a horrifying turn ... cops say gunfire has broken out at the party -- and multiple people have been wounded.

The Kansas City Police Dept. said in a statement that shortly after Travis Kelce and Patrick Mahomes addressed the hundreds of thousands of K.C. supporters at Union Station ... gunfire erupted around a garage nearby.

According to cops, "several people were struck" by bullets ... though it's unclear the severity of their injuries.

Cops say "two armed people" have been "detained for more investigation."

Authorities are now urging everyone to leave the area "in order to facilitate treatment of shooting victims."

Video from the scene shows just how horrifying things got ... you can see in footage multiple cops had their guns drawn as they raced inside Union Station to deal with the matter.

The KCPD said in its statement the officers were "working to provide for the safety of everyone inside union station and expedite care of those injured."

NFL Network's James Palmer, meanwhile, said he and his colleagues were initially instructed to get under a stage after the gunfire erupted. Minutes later, though, they were escorted from the scene.

Following the mayhem, Chiefs linebacker Drue Tranquill posted prayers on his X page for those injured ... writing, "Pray that doctors & first responders would have steady hands & that all would experience full healing."

Mahomes also posted prayers on X ... writing, "Praying for Kansas City…"