Widespread euphoria became mass panic on Wednesday as the Kansas City Chiefs and hundreds of thousands of fans celebrated the team's back-to-back Super Bowl titles with a parade near downtown Kansas City.

Toward the end of the event, gunfire erupted near Union Station, sending fans to run for cover to avoid being the victim of another mass shooting in the United States. Two armed gunman have reportedly been detained by local law enforcement in connection with the shooting, which left one dead and 12 injured—including 11 children.

Kansas City mayor Quenton Lucas, a Democrat, addressed the media Wednesday afternoon once the scene had been contained by police and paramedics.

“We went out today, like everyone in Kansas City, looking to have a celebration. That celebration was marred by a shooting,” he said, per Andrew McCarty of The Spun. “This is absolutely a tragedy, the likes of which we never would have expected in Kansas City.”

Kansas City's city council recently passed new gun control measures to combat a surge in local homicides. The ordinances ban certain weapons like machine guns, firearm silencers and guns that can be turned into automatic weapons and also make it illegal to transfer guns and ammunitions to minors.

The state of Missouri, led by Republican governor Mike Parson and a Republican-controlled Senate and House, has recently worked to further loosen some of the most lax gun control laws in the country, not requiring a license for gun owners, registration for single guns, background checks for private sales, nor permits for concealed and open carry. Missouri also does not prohibit people convicted of misdemeanor domestic violence nor people subject to domestic violence restraining orders from purchasing firearms.

State legislators passed the Second Amendment Protection Act in 2021, which penalized police for enforcing federal gun laws on Show Me State ground. It was ruled unconstitutional in March, a decision currently being appealed by Republican Attorney General Andrew Bailey.

According to Lucas, there were 600 Kansas City police officers and 250 additional law enforcement personnel from other agencies on scene at Wednesday's parade. Viral video from the scene allegedly shows fans tackling one of the alleged gunmen with a group of police officers standing nearby.

“I’m heartbroken,” Lucas said. “I was there with my wife, I was there with my mother, we never would have thought that we, along with Chiefs players, along with fans, hundreds of thousands of people, would be forced to run for our safety.”

Missouri has the United States' ninth-highest rate of gun deaths among states, per the CDC, with 1,414 people dying at the hands of gun violence in 2021 alone.