A boating accident near Alcatraz Island in California left one man dead and three of his family members missing.

SAN FRANCISCO — The man who died after a boat sank in the San Francisco Bay near Alcatraz Island was a former reserve deputy with the Sutter County Sheriff’s Office in California.

The boat sank Tuesday, and one man was pulled from the water but later died. Sixteen others were rescued Tuesday afternoon, but rescuers are still searching for three people who remain missing. 

On Wednesday, the Chief Medical Examiner for the City and County of San Francisco identified the man who died as Clifford Joseph Boisa, 79, of Sutter County. 

The Sutter County Sheriff’s Office said Boisa served the department and the community from 1987 to 2001.

Ralph Boisa, Clifford’s younger brother, said his extended family and a few close friends were on his younger brother’s boat Tuesday afternoon to celebrate the life of his daughter who died over a decade ago and was in her 30s and loved to surf.

“We’ve gone through a lot of tragedy over the years,” Boisa, who lost his other daughter in 1995, told the Associated Press. He lives in Washington and couldn’t make it for the excursion. 

The three people missing are his sister Carol, Clifford’s wife Jackie, and his daughter’s friend, he said. Clifford’s dog also died.

Officials said the boat was home-ported in Stockton, California and several members of the Stockton Yacht Club say the Boisa family are members.

Authorities say the boat, a 50-foot pleasure craft, capsized amid swells up to 5 feet. The U.S. Coast Guard is leading the search for the three missing people with vessels and aircraft. 

Ralph Boisa said his brother John is a “very capable and experienced boatsman” who served in the U.S. Navy. He frequently took family members out on the boat to the San Francisco Bay, Boisa said.

U.S. Coast Guard Captain Jared S. Toczko said rescuers will continue searching until sundown Wednesday before ending rescue efforts.

The Associated Press contributed to this report.