Police are investigating after fans at a preseason 49ers versus Raiders game turned violent in a series of incidents that included two parking lot shootings and a bathroom beating that left a man unconscious Saturday.
Two of the three men initially had life-threatening injuries but today were upgraded to fair condition, according to San Francisco General Hospital.
YouTube videos showed other rowdy fans captured at the event -- an intense, multi-person fist fight occurred in the stands, and a man holding a beer and wearing a Raiders jacket yelled an obscenity at 49er players as he stood in the front row.
It's the second time in less than five months that California fans have turned dangerously violent, perhaps spurred by alcohol.
"It's up to teams to protect their fan base. Clearly, many are dropping the ball," said Brian Frederick, executive director of the lobbying group Sport Fans Coalition. "There's no doubt that excessive alcohol can help fuel these fights, but I don't see the owners wanting to remove alcohol from the equation, because they're making too much money off of it."
In March, a Giants' fan was brutally attacked in the parking lot after the Dodger's opening day game. Bryan Stow, a paramedic from Santa Cruz, Calif., who wore a Giants shirt at the time of the attack, suffered brain injuries and remains hospitalized in serious condition. The two men accused of the beating have pleaded not guilty.
Following the incident and much public scrutiny, Dodgers officials installed additional lighting in parking lots, increased police presence during games and added "behavioral protection" security officers who monitor the crowd for drunks.
In the parking lot attacks on Saturday, a man allegedly wearing a "F--k the Niners" T-shirt was shot several times in the stomach. He managed to stumble to stadium security for help, according to police. Another man suffered less serious injuries in a separate shooting.
"I don't know if the victims were there for the game. I don't know if they are 49ers or Raiders fans," Sgt. Michael Andraychak said in a statement.
Police say they're looking for a person of interest related to one or more of the shootings and a suspect in the assault case. No arrests have been made, according to Andraychak. The 49ers issued a statement saying they were working with police.
"The 49ers' primary concern has always been, and will continue to be, providing a safe and enjoyable environment for our fans on game day," the statement read.
San Francisco Mayor Edwin Lee and Oakland Mayor Jean Quan issued a joint statement vowing to prosecute to the full extent of the law and calling the incidents "completely unacceptable."
"These games are family events and the types of images we witnessed last night have no place in our arenas," the statement said.
Also in California, Rose Bowl officials recently banned alcohol at tailgating parties. The move came eight months after two men were stabbed in the parking lot before a USC-UCLA football game.
The Associated Press contributed to this report.