CHICAGO (CBS) — A man is dead after being stabbed in a fight at a restaurant-bar in the Portage Park community Sunday evening.

The incident happened around 6:50 p.m. at The Foundation Tavern & Grille, located at 5007 W. Irving Park Rd.

Police said two men, ages 35 and 37, were involved in a quarrel that turned physical.

Witnesses said they heard yelling and screaming from the kitchen, and then the older man stabbed the younger man repeatedly with a knife, police said.

The 37-year-old assailant was arrested, and the 35-year-old victim was taken to Advocate Illinois Masonic Medical Center in critical condition, police said. He was later pronounced dead at the hospital.

Sources said both the victim and the assailant were employees of the business. Police said it’s not yet clear what prompted the argument and stabbing.

Foundation Tavern was closed on Monday, as is normal for the restaurant, but a worker could be seen inside, wiping down the back of the business. He told a reporter he had no clue about what happened Sunday night.

Area North detectives are investigating.