Some teens have said they play the knockout game just "for the fun of it" or to show they have a powerful punch. YouTube

A disturbing street game gaining popularity among teens has turned deadly.

The “Knockout Game,” which involves randomly targeting pedestrians and knocking them out with a single punch, has been the cause of deaths in multiple U.S. cities including Syracuse, N.Y.; St. Louis; and Hoboken, N.J.

The move, known as the “one-hitter quitter,” where one punch renders an unsuspecting person unconscious, is the ultimate goal, according to a report by CBS 2. Some of the attacks have been caught on camera, showing teens hitting strangers and walking away as the victims lie motionless on the ground.

Teens interviewed about the fad say they partake in the violent game “for the fun of it,” one teen told the news outlet. “They just want to see if you got enough strength to knock somebody out.”

For some, their strength is lethal. In May, two teenagers in Syracuse struck 51-year-old Michael Daniels and stomped him to death. A 15-year-old and 13-year-old were later arrested, the Syracuse Post-Standard reports.

"It's the randomness," Syracuse Mayor Stephanie Miner said. "That's what takes your breath away."

Other incidents of the knockout game have popped up in Massachusetts, New Jersey and Illinois.

But the game is not exactly new. In 2011, a 72-year-old St. Louis man was randomly targeted and punched hard enough to knock him to the ground, where he suffered a fatal head injury. Elex Murphy, now 20 years old, was handed down a life sentence plus 25 years in prison for the attack.

St. Louis Assistant Circuit Attorney Christine Krug said the “knockout” attack still resonates in the city.

“This kind of shook a community to its core,” she said, explaining that many feel that “you can’t even walk to the grocery store in broad daylight without fear of being attacked.”

In New Jersey, video footage shows 46-year-old Ralph Santiago targeted by a group of teens. He was later found dead with his head lodged between two iron fence posts. “His neck was broken,” Geovany Sepulveda of the Hoboken Volunteer Ambulance Squad, one of the first responders, told the Jersey Journal.

Thomas Sowell, a senior fellow at the Hoover Institution, Stanford University, points to the fact that the “knockout game” has racial underpinnings that the “mainstream media” has failed to describe. The game, which “has been played for years,” often targets Jews, “whites in general or people of Asian ancestry,” he said in an op-ed for the New York Post. He describes an attack in Milwaukee where attackers were heard saying, “White girl bleed a lot.” In Illinois, the game is often called “polar-bear hunting.”

Recently, a series of attacks in Brooklyn, N.Y., saw teens targeting the Jewish community. The NYPD says there were separate incidents, including one caught on camera, where teens have targeted men dressed in traditional Jewish dress and punched them to the ground.

One man, who did not want to be identified, told CBS 2 his 12-year-old son was recently attacked. “One, full-strength with his fist, whacked him, punched him, on the side of the face, full force,” the man said. Once knocked on the ground, the boy reportedly heard the group yell in a "hysterical, happy shout, ‘We got him,’” the man said.

On Nov. 10, a similar attack took place on a 19-year-old Jewish man. “He was actually holding an expensive camera. And they punched him and nothing was stolen,” Rabbi Yaacov Behrman said. The incident, caught on surveillance footage, shows a man being knocked to the ground by a group of teens.

“I think there have been a total of eight since September, middle of September,” Police Commissioner Ray Kelly said, referring to the number of “knockout” attacks.

Dr. Fahd Ali, a trauma surgeon at Upstate University Hospital in Syracuse, says troubled children often don’t understand the real consequences of acts of violence.

"These kids don't see the victims who never wake up,” Ali said in an interview last year. "They don't see the people on ventilators or the people who die from bedsores or pneumonias that eat their lungs out because they can't breathe. They don't see the kids long forgotten by their friends on the streets, the ones who've lost the ability to wipe the corners of their mouths when they drool."

For Sowell, the key is to stop the attacks altogether, fearing they will spread.

“Some in the media, as well as in politics, may think that they are trying to avoid provoking a race war by ignoring or playing down these attacks. But the way to prevent a race war is by stopping these attacks, not trying to sanitize them,” he wrote.