Alcatraz Cruises guest supervisor Tony Bermudez was equally stunned.
"It was almost like surreal," he told KTVU. "I mean, I've seen movies, sharks, other things going on. But to see it in front of you is just amazing. For this to happen is like a maybe once in a lifetime, right from Alcatraz."
David McGuire, Director of the San Francisco-based shark conservation group Shark Stewards and a research associate at the California Academy of Sciences confirmed the event's importance.
"This is the first recorded predation event by a white shark I'm aware of in the San Francisco Bay," he said in an article on the organization's website. "It is definitely a white shark, about 8–10 feet, based on the video sent to us. The tourists were very excited."
As for the shark's victim, McGuire believes that it was either a California sea lion or a harbor seal.
Now many are wondering if it is safe for people to swim in San Francisco Bay, especially since the attack happened so close to shore.
Sharks, Humans Living So Close; Why Not More Attacks?
McGuire isn't too worried, though.
"For me its pretty exciting and a sign that the health is returning to the San Francisco Bay ecosystem," he said. "We swim in the Bay every day at the Dolphin Club without a shark encounter. It's why we call this month Sharktober."
"The risk of shark attack is extremely low. Over eighty swimmers from the Dolphin Club and South End Rowing Club swam from Alactraz last week, and another race is scheduled for next weekend. It is up to the leadership what to do, but I suspect this shark is well fed and long gone."