Two adults and two children were critically injured Sunday in a two-car crash on the southbound 405 just south of Seal Beach Boulevard.
The accident occurred just after 2 p.m., when the two cars collided, causing one of the cars to roll over several times, Orange County Fire Authority Capt. Marc Stone said.
The four critically injured passengers, who were traveling in the car that rolled over, were helped from the car by passersby who saw the accident and stopped, Stone said. The two children were taken to Miller Children's Hospital in Long Beach, while the two adults were taken to the UCI Medical Center in Orange. The driver of the other vehicle was taken to Los Alamitos Medical Center with minor injuries, Stone said.
The cause of the accident is being investigated by the California Highway Patrol. Five ambulances and the Freeway Service Patrol responded to the scene. Stone said.