It happened just before 10 p.m. on Saturday at the Marquis Lounge on West Highland Avenue.
Police say a total of five people were shot, one of whom died at the scene, according to investigators.
The others were sent to the hospital for treatment. Their condition is unknown.
It's unclear what led up to the shooting and police told Eyewitness News there is no information on a suspect or suspects.
ABC7 video from outside the bar early Sunday morning showed a heavy police presence and several streets blocked. Drivers are urged to seek an alternate route as officers continue their investigation.
Anyone with information is urged to contact police.
This is a developing story. This article will continue to be updated as more information becomes available.