A boat suspected of smuggling immigrants from Mexico overturned Sunday in California, killing one man, and three others were rescued, authorities said.

The 30-foot boat of the type known as a panga was spotted capsized shortly before 1 a.m. near the Ocean Beach pier in San Diego, authorities said.

Three men were rescued and taken to the hospital in stable condition, said Lt. Ric Stell of the San Diego Lifeguard Service.

Several other people may have made it to shore and fled, authorities said.

It wasn’t clear how many people had been aboard the boat, a low-slung open fishing-type boat often used for smuggling. The seas were high, with 8-foot waves, authorities said.

Another boat was spotted near Point Loma at around 3 a.m. and the U.S. Border Patrol arrested all 15 people aboard were arrested for allegedly trying to enter the U.S. illegally, KNSD-TV reported.

Last Monday, 72 people were taken into custody after three panga boats were spotted in Point Loma, U.S. Customs and Border Patrol told the station.

“We have seen that smugglers are bringing in larger groups and putting them in more remote and dangerous areas,” Alfonso Martinez, deputy chief of the Border Patrol in San Diego, told the station.