“Oh, yeah, some n----- is coming to town.”

That’s what Sgt. Jack Axium, a white Chicago police officer, said. There’s no dispute about that.

Axium was amid a group of cops preparing for an Oct. 27, 2015, visit by President Barack Obama to see LeBron James and the Cleveland Cavaliers play the Bulls at the United Center.

The comment outraged another cop, who is biracial and who filed a complaint against Axium.

Axium quickly admitted making the incendiary statement, later saying it was “in the heat of the moment.”

The slur required a harsh punishment, according to police Supt. Eddie Johnson. He wanted to suspend Axium without pay for nine months.

But Axium ended up avoiding any punishment at all, records obtained by the Chicago Sun-Times show.

For three years, Axium fought the proposed suspension, remaining on the job, collecting his paycheck and boosting his pension.

His legal challenges finally ran out late last year, as the Chicago Police Board prepared to move ahead with the disciplinary case against him.

But before the police disciplinary board acted, Axium, a Chicago cop for 25 years, put in his retirement papers.

So the police board closed the case a few weeks ago. It had to. It can’t punish someone who’s no longer a city employee.

Axium, 52, has begun taking his Chicago police pension. Now amounting to $72,526 a year, his taxpayer-funded retirement pay will increase by $1,088 every year beginning in 2026.

Mayor Lori Lightfoot was president of the police board when Johnson tried to suspend Axium. She’s incensed by the sergeant and his successful efforts to avoid being held accountable for his racist words, which sparked an investigation by the city’s old Independent Police Review Authority.

“The reprehensible and racist comments made by this individual have no place in the police department, let alone in Chicago,” according to a written statement from Lightfoot’s office. “During this time, the Chicago Police Board was barred from ruling on discipline related to this sergeant’s actions while a similar case was facing legal challenges in the court system. The mayor, CPD and the Chicago Police Board are committed to ensuring all delays in the disciplinary process are reduced to a minimum to ensure officers in violation of the code of conduct will be held accountable for their actions.”

Axium, a married father of three who lives on the Northwest Side, didn’t return calls seeking comment.

According to police spokesman Anthony Guglielmi, the three-year process to bring Axium before the police board “is the length of time to complete that process in accordance with collective bargaining rules, officers’ legal rights and formal charging process.”

Obama was in Chicago that fall day in 2015 to speak to the International Association of Chiefs of Police, attend a couple of political fundraisers and take in a Bulls game.

Hours before the game, Axium and other tactical officers gathered at the 12th District police station at 1412 S. Blue Island Ave., where Sgt. Gregory Noncz chewed them out for being late for the Obama assignment, according to IPRA records. When Noncz left the room, “Several police officers stated, ‘Oh, we have something going on today,’ at which point it is alleged that . . . Axium stated, ‘Oh, yeah, some n----- is coming to town.”

Records show Officer Anthony Santiago was so upset by the remark that he kicked a garbage can, said he is Hispanic and African American and called Axium a racist. Axium said he didn’t see Santiago in the room, apologizing for the remark.

After Santiago filed a formal complaint, Axium acknowledged, when he was interviewed by IPRA on April 21, 2016, that he used the N-word.

“As I was putting my stuff away in my locker, gentleman, who I don’t know who it was, said to me, ‘Something going on?’ ” according to a transcript of Axium’s interview. “I turned without acknowledging who that was ’cause I didn’t know who it was, turned to my left and said, ‘Ah, some n----- going to watch another basketball game.

“At which time I heard someone yell, ‘Ah, this is bull----.’ I heard a loud noise, which I saw was Officer Santiago kicking the garbage can . . . Started m-----f---ing me, at which time I said, ‘Officer Santiago,’ I said, ‘if I offended you in any way, I apologize.’

“I don’t know why I used that word,” Axium told investigators. “I blurted it out. Heat of the moment, I guess, yeah.”

Sharon Fairley, a former federal prosecutor who ran IPRA, says she initially wanted to fire Axium. “There’s a difference between saying something bad about the president than using a racially denigrating word at the police station,” Fairley says.

But after talking with Axium and his lawyer, Fairly recommended a nine-month suspension, which Johnson forwarded to the police board.

But Axium’s disciplinary case was delayed by a lawsuit filed by the Chicago Police Sergeants Association on behalf of Sgt. Sam Cirone, who was facing a one-year suspension for his role in fabricating a police report to justify closing the investigation of David Koschman’s death without seeking criminal charges against former Mayor Richard M. Daley’s nephew Richard J. “R.J.” Vanecko for delivering the fatal punch.

A grand jury impaneled by a special prosecutor later indicted Vanecko, who pleaded guilty to involuntary manslaughter and served two months. Though the special prosecutor, Dan K. Webb, criticized the police, no officers were charged.

The sergeants union argued that an arbitrator had to decide any proposed suspensions longer than 30 days and not the police board. Cirone and the union lost that argument last year. The police board plans to consider Cirone’s proposed one-year suspension in August.