The 40-foot (12-m) boat had been pummeled to pieces by the surf by the time rescue boats arrived, said Rick Romero, lifeguard lieutenant for San Diego Fire-Rescue.
Several people were pulled from the water, and some required life-saving efforts on the beach. There had been about 30 people on the boat in severely crowded conditions without adequate safety equipment, authorities said.
“Every indication from our perspective is that this was a smuggling vessel, used to smuggle migrants into the US illegally,” said Jeff Stephenson, a Border Patrol agent.
The nationality of the people on the boat was not immediately known, Stephenson said, who added that the captain was in custody and speaking with investigators.