WHEATON, Ill. — An apparent argument at a popular pub in unincorporated Wheaton on Friday morning ended in a shooting that left one man dead.

The DuPage County Sheriff’s Office (DCSO) said they responded to a shooting at Rosie O Reilly’s Pub, 0N131 Gary Ave., just before 8:45 a.m. on Friday. Witnesses described what seemed like an argument happening inside the pub, which eventually resulted in a fatality.

A spokesperson for the DCSO confirmed the homicide, but the identity of the man who died is being withheld, with an autopsy pending from the DuPage County Coroner’s Office.

Earlier Friday, Rosie O Reilly’s owner John Dwyer confirmed to WGN that a man died in the incident. SkyCam 9 also captured images of the aftermath, including spent shell casings scattered across the pavement and deck behind Rosie O Reilly’s.

The victim was evidently well-known to the owners and patrons of the pub. Described as a friendly guy, WGN was told he leaves behind two children, with another on the way.

Dwyer struggled to understand how such a tragedy could unfold so suddenly.

“This could happen anywhere, anytime, for the smallest of reasons,” he said. “And this is a perfect example.”

“I don’t know. We don’t know.”

According to witnesses, two individuals seemed to be arguing inside Rosie O Reilly’s on Friday morning then decided to go outside. Dwyer said one of the individuals then went to get his gun.

Cell phone video obtained by WGN, however, showed a perplexing scene. The victim and another man were seemingly horsing around on the pub’s outside deck, at one point dancing together as if music was playing.

“One minute they’re arguing, the next minute they’re hugging,” Dwyer said.

Then came gunshots.

“The guy who went to get his gun shot two shots in the air,” Dwyer said.

Moments later, according to witnesses, a gunshot struck the victim on the forehead, a wound that proved to be fatal.

Yet witnesses said the two men who were outside with the victim, including the individual who fired the weapon, didn’t try to flee the scene as pub patrons called 911.

“They just stayed right there,” Dwyer said.

DuPage County Sheriff’s investigators are reportedly in possession of the pub’s surveillance video, which could help shed some light on what happened there Friday morning that left a man dead.

The DuPage County Sheriff’s Office did report the scene was immediately secured and everyone involved, including the alleged shooter, is in custody. Officials say this was an isolated incident and there is no threat to the public.