According to one witness, the incident happened late Tuesday night while a realtors convention was being held in town.
Minh Nguyen said he was near the food court when the violence broke out.
"There was a lot of physical violence. There was a chair that was smashed against someone. Someone threw punches, there were sucker punches," said Nguyen. "We had to jump the railing and I helped my friend down. There was physical violence happening inside and outside the food court."
The REALTORS Triple Play Convention and Trade Expo, which was happening last week, put out a statement saying that the incident at Harrah's was not affiliated with any official TriplePlay events, adding that Harrah's was not a convention headquarters nor was it an overflow hotel for the 2021 convention.
Atlantic City police did respond to the casino around 3 a.m. Wednesday, but they say no one wanted to sign a criminal complaint.
Jeff Fox saw the video and has attended conventions in Atlantic City for decades.
He says outside entities typically hold networking parties at night, but it's unclear if any of the people involved in the fight were attending a conference or an outside party. Still, Fox says just seeing the video was disheartening.
"Once it starts, it spirals, and then people get sucked into the action. It's really sad. When I saw that I was a little disappointed," said Fox.
One person was treated for non-life-threatening injuries.
Harrah's Casino is owned by Caesar's Entertainment. Action News reached out to the parent company for comment but we have not heard back.
A previous version of this story incorrectly stated that the event was connected with the National Association of Realtors.