Two people died Saturday morning in what authorities suspect was a smuggling event involving a panga boat off the coast of Imperial Beach in San Diego County, according to U.S. Customs and Border Protection.

Around 6 a.m., Imperial Beach Fire and Rescue responded to a panga boat that tipped over near Cortez Avenue and Seacoast Drive. Officials say several people were on board.

“It took the whole call, was just about an hour and a half long,” said Imperial Beach Fire and Rescue Capt. Patrick Spears.

Spears said they arrived to find multiple agencies there, including Imperial Beach and San Diego lifeguards, U.S. Coast Guard and U.S. Border Patrol.

“We broke off into medical groups, then we are in charge of triaging all the patients, treatment and arranging transport to local hospitals,” Spears said.

Spears added that Border Patrol had seven people in custody. Imperial Beach lifeguards pulled two people from the water, both of whom had died.

The large surf at the time made the rescue more challenging.

“Six to eight-foot waves… it was just massive pitching the waves, so the boat was probably just tossed and all the individuals immediately submerged,” Spears said.

At the time the incident happened, there were several surfers in the water. They saw the people in trouble and started to rescue them, according to Spears.

Officials say they believe there is one more, a tenth person, missing.

Officials have not yet released the identities or information about the people involved. It’s also unclear where the boat came from or where it was headed to.