A video of a white man being punched after he allegedly called a black man the n-word on the platform of a Blue Line CTA station has caught fire on social media.

In the video, which was taken on Thursday afternoon, a man in a pink tank top can be heard taunting a black commuter at the Clark/Lake station.

After eyewitnesses said the white man used the n-word, the black man can be seen calmly removing his button-down shirt and glasses before socking him.

The punch knocked the white man back and left him dangling over the edge of the platform above the train tracks.

It appears he gets hit again twice by the same man. With the punches, the white man was knocked into the pit, next to the tracks as the crowd erupts into screams.

“Call another motherf—– a n—–,” the black man yells in the video as he towers over the white man. “F— wrong with you?”

The video ends as some people gather on the platform near the white man and help him back up. The video has gained thousands of views across Twitter, Facebook and Instagram.

The man who shot the viral video said he was making his usual Blue Line transfer when he saw the situation unfold.

“Nowadays you hear an argument and you already know, the first thing that comes to mind is ‘start recording'” said the man, who didn’t want his name to be used.

He said he saw the black man hit the white man three separate times: first, when they’re both standing; second, when he got on top of the white man and yelled; and third, when the white man was knocked into the pit. After the white man was helped up on the platform, the white man walked away, he said.

“Nobody has the right to use that word in any manner,” the man who recorded the incident said on Friday.

Thousands of commenters have debated whether the black commuter was justified in throwing the punch. Many have also voiced their support.

Mike Kemper, a 27-year-old engineer, said he stepped onto the Blue Line platform about 15 seconds before the confrontation started.

“My first reaction was … Yeah, [the white man] deserved that” Kemper said. “I thought it was well-deserved.”

Kemper said when another black man tried helping the white man up with others, the white man began yelling slurs and hurling insults at that man too.

“He kept yelling until he was out of earshot,” Kemper said. He added a friend appeared to be guiding the white man away from the crowd.

Kemper said he thought the white man was intoxicated.

In response to questions about the incident, CTA officials referred the Sun-Times to Chicago Police.

CPD News Affairs Officer Norma Pelayo said officers arrived at the station about 2:20 p.m. in response to a call of a battery in progress, but found no victim at that time.

Police said as of late Friday afternoon, the man who was punched has yet to file a report.