Two people were killed and 15 others wounded Sunday in Kansas City, Mo., when a gunman opened fire on a line of people outside a bar, police said.

The shooting began about 11:30 p.m., following a disturbance among the crowd of people waiting to get inside the 9ine Ultra Lounge, southeast of the city’s downtown, Kansas City Police Chief Richard Smith said at a Monday news conference. The shooter killed one woman before an armed security guard confronted, shot and killed him, Smith said.

Authorities described “a chaotic scene” as hundreds fled the venue by foot and in cars, the violence shattering the city’s celebration of its football team, the Kansas City Chiefs, who had just advanced to the Super Bowl in what was “an exciting night, a euphoric night,” Mayor Quinton Lucas said.

“Last night was a night many people in Kansas City have been dreaming of for 50 years,” Lucas said at the news conference. “This is very disappointing for us. It’s heartbreaking.”

Authorities said the woman killed was 25-year-old Raven Parks, and they identified the shooter as Jahron Swift, 29. Police have yet to pinpoint a motive in the shooting. As of Monday evening, they weren’t sure whether Parks was targeted.

“A preliminary investigation shows that there was a line of people to get into the establishment and that the suspect approached the line and started shooting into the line,” Capt. David Jackson told reporters. “We don’t know if he was targeting a specific person or if there was a relationship or anything that led up to that.”

Later, Smith addressed an unsubstantiated theory circulating on social media alleging that the incident escalated from a confrontation over people cutting the line to get into the club, saying he did not know whether that rumor was true.

But Smith said police have discussed the club before, even bringing it up at a recent meeting to plan for security concerns in the event of a Chiefs win. A drive-by shooting outside the establishment last week made them wary, he said. Lucas said the city will inspect the club this week and determine whether its liquor license should be revoked.

“We will make sure that the bar won’t continue to be a nuisance long term,” he said.

In the hours before the shooting, a Facebook page associated with the 9ine Ultra Lounge advertised an event called “Sold Out Sundays,” which appeared to be a celebration of the Chiefs’ victory over the Tennessee Titans in the AFC Championship earlier that day. Posts on the page promised a packed venue and advised patrons to arrive early.

On Monday night, the club said in a statement it was “deeply saddened by the unsavory tragic act of one individual last night.”

“This shameless and senseless act of violence claimed the live of one of our patriots and injured many others and quite frankly, we have little in the way of answers,” said the statement, which was posted to Facebook and signed “9ine Ultra Lounge Ownership.”

The shooting in Kansas City was among violent incidents throughout the United States on Sunday.

On Sunday morning, two police officers in Honolulu were fatally shot near the base of a volcanic crater. A fire was started and quickly spread, destroying five homes. A neighbor told the Associated Press that a woman who had filed four days earlier to evict the alleged gunman had left in an ambulance with stab wounds.

The two slain officers were Tiffany Enriquez, who was with the Honolulu police for seven years, and Kaulike Kalama, who was on the force for nine years, Honolulu Police Chief Susan Ballard said at a news conference Sunday.

Another shooting Sunday night inside a San Antonio club left two dead and five injured after an assailant began firing “indiscriminately” inside, police said. All of the victims were patrons.

That incident was apparently preceded by an argument, though police provided few details. Police had arrested a suspect in the shooting on Monday.

In Kansas City, the police chief and the mayor pleaded for the public’s help in putting an end to gun violence, encouraging more communication with law enforcement.

“We’ve got a problem in Kansas City,” Lucas said. “We’ve said a few times that it is an epidemic of gun violence. We’re losing too many lives. We have too many people shot each year.”

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