Alcatraz boat victim identified as 79-year-old; search continues for 3 missing people

A former California reserve deputy sheriff has been identified as the person who died after a pleasure boat carrying members of an extended family capsized in the frigid waters of San Francisco Bay near Alcatraz Island.

Clifford Joseph Boisa, 79, of Sutter County, died after the three-level recreational vessel sank Tuesday afternoon with 20 people aboard, authorities said. The Sutter County Sheriff's Office confirmed to Fox News Digital that Boisa served as a reserve deputy sheriff beginning in 1987.

Three passengers remained missing Wednesday as the U.S. Coast Guard and local agencies continued an extensive search of the bay. Sixteen others were rescued, including three people who were taken to local hospitals.

The passengers were members of an extended family gathered for a memorial service that included scattering a loved one's ashes in San Francisco Bay, according to a report from The New York Times.

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San Francisco Fire Chief Dean Crispin said crews were dispatched at about 3:35 p.m. local time after receiving reports of a vessel fire roughly 600 yards off Alcatraz Island between the former prison and the Golden Gate Bridge.

When first responders arrived, they found no evidence of a fire, but instead discovered the boat had capsized and was already mostly submerged.

Crispin said the San Francisco Police Department's marine unit found the vessel with only its upper deck above the water. The boat's engine was still running, and fuel was leaking into the bay.

One person was found in the water, while the remaining occupants were located inside the vessel's top compartment before rescuers pulled them to safety, he said.

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Authorities have not yet determined what caused the boat to sink. However, officials have said strong summer winds and rapidly changing conditions on San Francisco Bay can create dangerous boating conditions.

Commercial fishermen Mike Montoya and Justin Marceline, who rushed to help after the vessel went down, described a frantic rescue as passengers fought to escape.

"There was even people banging at the windows as they were like filing out, and as soon as people were hitting the water, we were just trying to pick them up as fast as we can," the fishermen told NBC Bay Area. "Some people didn't even have life vests on and they were drowning."

The Coast Guard and San Francisco Fire Department continued searching Wednesday using boats, helicopters, thermal imaging, tide predictions and drift modeling to find the three missing passengers.

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The Sutter County Sheriff's Office told Fox News Digital it had no additional information to provide about Boisa. Fox News Digital also reached out to the San Francisco Fire Department for additional information.

Officials said the vessel departed from the area near San Francisco's St. Francis Yacht Club. The cause of the sinking remains under investigation.

Boisa's family did not immediately respond to Fox News Digital's request for comment.

Fox News Digital's Michael Sinkewicz contributed to this report.