At least four people have been killed and others are being treated for gunshot wounds after a mass shooting at a popular bikers’ bar in California’s Orange County. The Orange County sheriff said those killed included the suspected gunman, with local TV station KCAL News reporting that the incident began with a domestic dispute between the gunman and his wife. Local media reports described the shooter as a retired law enforcement officer. California governor Gavin Newsom was monitoring the shooting “and coordinating with local officials as more details become available,” his office tweeted. Cook’s Corner is a popular, longtime watering hole for the biker community in Southern California. Many motorcycle riders and enthusiasts gather there on weeknights and during the weekend for live music, open-mic nights or just a cold beer after a long ride. Hours before the shooting, customers were stopping by for an afternoon drink and meal. Rows of motorcycles and bikes framed the gravel entrance as plaques described the storied history of the bar built in 1884.