YouTube star and "The Voice" contestant Christina Grimmie was shot by a man inside The Plaza LIVE in Florida Friday night, police said.
The gunman is dead and Grimmie remains in critical condition, according to police.
Twitter users reported hearing at least six gunshots inside the venue, which was slated to host pop-rock band Before You Exit and Grimmie.
Police said the shooter had two guns and started to open fire as Grimmie was signing autographs for fans.
Grimmie's brother was able to tackle the shooter, who then shot himself.
A heavy law enforcement presence remains at the scene.
No other suspects are being sought. Police have not identified the shooter.