The waters off Alcatraz Island — famous for holding America's most dangerous prisoners in another era — swallowed a different kind of tragedy on Tuesday. A 50-foot, three-deck cabin cruiser carrying 20 people participating in a memorial service capsized in the rough chop of San Francisco Bay, killing one man, sending three others into the bay where they remain missing, and triggering one of the most extensive maritime rescue operations the city has seen in years.

Thirteen people were pulled to safety. Three more were transported to hospitals with injuries serious enough to require treatment, though they were expected to be released Tuesday night. One person was found in the water in "severe distress," according to San Francisco Fire Chief Dean Crispen — pulled aboard a rescue vessel, given CPR, and ultimately declared dead. The victim was identified Wednesday as Clifford Joseph Boisa, a 79-year-old resident of Sutter County, according to a representative for the Office of the Chief Medical Examiner.

A dog that was also aboard the vessel did not survive.

Twenty People, One Wave, and Chaos on the Water

The cabin cruiser, based out of Stockton and launched from San Francisco's St. Francis Yacht Club, may have been struck by a wave in the notoriously difficult waters of San Francisco Bay when it capsized, authorities said. The exact sequence of events that sent the vessel down was still being investigated Tuesday night, but the immediate scene that first responders encountered when they arrived left little room for ambiguity about the severity of what had occurred.

"When first responders arrived, some people were in the water, others were on the sinking boat and others were falling into the water," Crispen told reporters at a Tuesday evening news conference — a description of controlled chaos that demanded an immediate and massive response.

All passengers aboard were described as adults, most of them family members who had gathered to conduct a memorial service on the bay. "Our understanding was there was some kind of memorial service that they were engaging in. That's why they were using this particular vessel," Crispen said — a detail that adds a dimension of grief upon grief to an already devastating event.

Rescuers in Full Rescue Mode

The response to the capsizing was immediate and sweeping. Crispen said firefighters were operating in "full rescue mode," with 11 boats and divers deployed as part of the maritime response. Local police departments and private vessels joined the effort, expanding the search perimeter across the bay's cold, wind-driven waters.

Helicopter video from NBC Bay Area captured the scope of the operation — rescue boats moving through debris-strewn water, the remnants of what had been a boat full of people marking a loss now compounding that loss in ways no one could have anticipated.

Coast Guard Lt. John Corvino confirmed Tuesday night that the search for the three missing people would continue through the night, with searchers scanning the water from both the air and the surface. The bay's currents — predictable in their patterns to trained searchers — guided crews toward areas where survivors drifting in the water would most likely have been carried.

"We are going to continue for hours to make sure that we find these missing people, if possible," Crispen said.

The City Responds: 'All Hands on Deck'

San Francisco Mayor Daniel Lurie addressed the crisis with the directness of an official who understood the stakes. "This is an all-hands-on-deck search and hopefully rescue," Lurie said — choosing the word "hopefully" with the careful precision of a mayor who knows that every hour in cold bay water diminishes the odds for those still missing.

Crispen was equally candid about the physical challenges the search was operating under. At this time of year, he noted, whitecaps from persistent wind are typical in San Francisco Bay — conditions that make navigation difficult, reduce visibility, and complicate the work of divers operating below the surface. None of it, he made clear, would stop the search.

"Regardless of the wind, we're going to continue to search either way," Crispen said. "Our standard operating procedure is to continue to search as long as it's safe enough for us to search. This search will go on for some time."

The Shadow of Alcatraz

The capsizing occurred approximately a mile from Alcatraz Island, the former federal penitentiary that held notorious prisoners including Al Capone before closing in 1963 and transitioning to its current status as a national park visited by millions each year. The island sits in the middle of a bay known to mariners for its unpredictable conditions — strong currents, sudden weather changes, and waves that can build quickly when wind and tide align against a vessel.

On Tuesday evening, those waters were no longer merely a backdrop for one of San Francisco's most famous landmarks. They were a search zone, lit by spotlights and crossed by rescue vessels, while divers moved beneath the surface and helicopters swept overhead — all of them looking for three people who went into the bay on a day meant for remembrance and have not yet come back up.

The Alcatraz boat rescue operation was ongoing as of Tuesday night. The search, Crispen promised, would continue.