The incident happened around 10:30 p.m. at the restaurant, near the Ferry building on the Embarcadero. An 18-year-old woman was celebrating her birthday with a dance party.
Police say there was a confrontation in the bar area which turned into a fight, escalating in gunfire. A 19-year-old man and two girls, one 12, the other 15, were treated for gunshot wounds. They are all reported to be in serious but stable condition.
One party guest described the scene as chaotic.
"There was just shooting. I was just dancing. There was shooting and I was just dancing right there and everybody was just running. I was just trying to get the hell up out of there, okay?" Kochise Jones told ABC7. "So, I don't know what happened. It was shooting from the outside."
Investigators are still comparing notes after interviewing dozens of witnesses. Police arrested one man for being a felon in possession of a gun, but he is not being charged with the shooting.