The ride-hailing company Lyft admits it failed to comply with a city mandated warning system designed to weed out violent drivers — a failure that led to a traffic dispute, a fatal karate kick, murder charges and a fugitive fleeing to China.

Lyft acknowledged it did not notify the city that one its drivers punched a customer last year, allowing him to go on to drive for Uber, where he is accused of kicking a taxi driver weeks later in broad daylight.

Last week, Lyft “pleaded liable” to the municipal violation and agreed to pay a $10,000 fine — the maximum amount allowed, according to Isaac Reichman, spokesman for the Department of Business Affairs and Consumer Protection — the city agency charged with regulating ride-hailing companies.

Lyft was cited for failing to notify the agency that it had deactivated driver Fangqi Lu from its platform because of the alleged punching incident — even though it was required to do so within 48 hours.

Had the notification been made, the city would have immediately relayed a warning about Lu’s alleged violent behavior to other ride-hailing companies in Chicago, including Uber.

Lu, 31, was working as an Uber driver four weeks later when he fatally kicked taxi driver Anis Tungekar, 64, in the head following a traffic dispute in the West Loop.

Lu has since fled to China and been charged with murder in Cook County.

Lyft spokeswoman Campbell Matthews did not immediately respond to a request for comment on Monday.

In a statement after the citation was issued, she said: “This is a terrible tragedy, and our hearts go out to the friends and family of Mr. Tungekar.”

The city issued the citation against Lyft on June 18, shortly after the Sun-Times began asking whether a communication breakdown had occurred in the wake of Lu’s alleged violent behavior while working for Lyft.

Tungekar’s son, Omar, said the fine amounted to a slap on the wrist.

“Lyft’s plea confirms what we already knew: that ridesharing companies cut corners when it comes to safety and can continue doing so when the penalties they face are tiny compared to the billions they rake in,” Omar Tungekar, 36, said. “A $10,000 fine isn’t justice; it’s a joke. If we want to make ridesharing safe, we need tougher safety regulations to keep violent drivers off these platforms and penalties with real teeth.”

The alleged assault that Lyft failed to report to the city involved Chicago attorney Scott Gore, who said Lu’s punch left him with a bruised ear.

According to Gore, the blow occurred after he asked to get out of Lu’s vehicle short of his destination near Wrigley Field — a request that sparked an argument.

“He says to me, ‘You wanna fight?’ and I said, ‘You hit me, and I’ll sue you,’ and he hit me,” Gore told the Sun-Times. Gore reported the July 1, 2018, incident to Lyft.

Lyft took away Lu’s driving privileges the same day and two weeks later officially deactivated Lu.

Two weeks after that, on Sept. 2, Lu was picking up an Uber passenger when he became frustrated with Tungekar, whose taxi was double-parked outside a high-rise in the 500 block of West Madison Street, prompting Lu to reach out his window and hit Tungekar’s sideview mirror, according to police records.

Tungekar followed Lu about a block before pulling in front of his car at the intersection of Jefferson and Washington streets. Tungekar got out of his car and walked over to Lu’s driver’s side window, where the two exchanged words, surveillance video of the incident shows.

As Tungekar walked back to his car, Lu got out of his vehicle and kicked Tungekar in the head. As Tungekar crumpled to the ground, his head hit the pavement. He died two days later.

He fled to China before an arrest warrant for first-degree murder was issued Dec. 26 — nearly five months after the fatal kick.

The United States and China have no extradition treaty, so there’s little hope of bringing Lu back to face trial.

To the Tungekar family and their attorney, Mike Gallagher, the missed opportunity to sideline Lu was just another in a series of red flags that were not raised when they should have been.

Other missed opportunities were laid out in a lawsuit filed in June by the Tungekar family against Uber that accuses the company of negligently hiring and retaining Lu.

According to the suit, Lu’s driver’s license was expired and his history of violence was known to Uber.

Gore, the attorney who alleged he was punched by Lu, reported the incident not just to Lyft but to Uber and the Chicago Police Department as well, said Gallagher, who is considering adding Lyft as a defendant in the suit.