At least three individuals lost their lives when a boat capsized near San Diego on Monday, prompting a frantic search for additional victims by the Coast Guard and local sheriff’s deputies, according to authorities.

Beyond the three fatalities, at least four more individuals “were taken to our local hospitals via ambulance,” mentioned Encinitas Deputy Fire Chief Jorge Sanchez to NBC News.

A passenger on the panga vessel informed rescuers that there were 18 people aboard, but it remains uncertain how many might be unaccounted for or if any successfully reached the shore of Torrey Pines State Beach independently, Sanchez indicated.

“We’re just doing our due diligence by checking if there’s anybody else in the waters,” he added. “And to this point, I don’t have anything else to report, as far as missing or accounted for.”

The U.S. Coast Guard said in a statement that there are nine “missing individuals” following “a report of an overturned vessel” in the waters off Del Mar.

San Diego Sheriff’s deputies are also assisting in the “maritime event on the beach near the 200 block of Stratford Court, the law enforcement agency said.