ST. LOUIS – A Leadington police officer is on leave after shooting a man while trying to break up a large fight outside a downtown St. Louis bar around 3 a.m.

"25 to 50 people at least that were involved in the fight. Numerous onlookers. There was actual contact in the fight and there were people there that appeared to be armed," Major Janice Bockstruck, St. Louis Metropolitan Police Department, said.

Bockstruck said multiple officers from other jurisdictions were working security at The Wheelhouse for New Years Eve. According to police, people who were inside the bar went outside into the streets for a fight. The Wheelhouse was promoting a New Year’s Day brunch online, but it was not open on Wednesday and the owner never returned FOX 2’s messages.

"While it's very early in the investigation right now, it appears that officers potentially saved lives today with an armed person who was walking around a large fight and officers took action," SLMPD Public Affairs Director Mitch McCoy said.

Police say one of those officers from the Leadington Police Department shot and killed a 25-year-old after that man refused to drop a gun. SLMPD is investigating the shooting.

"We pretty much honor their investigation. Right now, he won't be working until that investigation is finished," Leadington Police Chief Jerry Hicks said.

Hicks says that officer has 18 years of law enforcement experience.

"Exemplary officer. Good officer. Above reproach as far as I'm concerned. He's been good for our department, good for the public," Hicks said.

A second person was grazed by a bullet but is expected to be okay.