At least three people were killed and nine others remain missing after a small boat carrying 18 people overturned near San Diego on Monday.

Four survivors were taken to local hospitals, while authorities, including the U.S. Coast Guard and San Diego Sheriff’s deputies, launched a large-scale search operation.

The boat, identified as a panga—a small, open vessel commonly used for smuggling—capsized off the coast near Torrey Pines State Beach.

Rescue teams are using helicopters, boats, jet skis, and ground crews to search for victims along the shoreline and in the water, NBC News has reported.

The number of people who may have reached shore safely is still unclear.

Written by B.C. Begley