CHP Officer DJ Sarabia said none of the eight people in the SUV was wearing a seat belt when the accident happened around 4:45 a.m. on the off-ramp from northbound U.S. Highway 101 to eastbound Capitol Expressway.
"It appears that either unsafe speed or unsafe turning movement caused them to lose control," Sarabia said.
He said the SUV rolled and that two people were ejected from the car, including the man who was killed.
The second person who was ejected suffered major injuries and was taken to a hospital along with a third victim, who had minor injuries, Sarabia said.
The other five people in the car suffered minor injuries but didn't require hospitalization, he said.
There were no children in the car, he said.
Sarabia said it appears that the family, who lives locally, was just getting back from Mexico when the crash happened. He said the man who was killed was sitting in the right rear passenger seat.
Investigators do not believe alcohol was a factor in the crash. Sarabia said the driver might simply have been going too fast on the slick roadway.
"It wasn't raining, but the roadway was wet at the time," he said.
The crash shut down the off-ramp for about two hours.