SUNSET PARK, Brooklyn (WABC) -- A violent argument inside a Costco in Brooklyn is now the subject of a police investigation.

The fight broke out in the aisles of the warehouse over the weekend and resulted in one person being knocked out before two others ran off.

The NYPD says it happened Sunday just before 4 p.m. at the Sunset Park location.

Police are looking at footage shared on social media showing two men arguing over a cart that escalated to one man hitting the other in the head.

Authorities say the 42-year-old victim also hit his head on a cart and was treated for injuries to his forehead and eyelid.

Costco members say, while violence is never the answer, the store itself and its parking lot on 3rd Avenue are regularly overcrowded.

"There's a lot of tension here, from the pa

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