Something went 'catastrophically wrong' in San Francisco Bay. What caused deadly boat sinking?

Something went 'catastrophically wrong' in San Francisco Bay. What caused deadly boat sinking? details a fatal incident involving the charter fishing boat California Dawn area under the Golden Gate Bridge, where a distress call came Tuesday near Alcatraz Island. Captain James Smith, who has 35 years of experience, said he saw what appeared to be steam or smoke and found a 49-foot motor boat rapidly sinking. Rescuers scrambled to pull 17 people to safety, but a man who received CPR on a San Francisco police boat was pronounced dead, while a female passenger was recovered Thursday and also died. Two passengers remain missing, and investigators have not yet confirmed the cause, though Coast Guard commander Capt. Jarod Toczko said survivors reported a wave hit the vessel and it listed then rolled over. Maritime experts cited by the newspaper said a single wave is unlikely to sink a large cabin cruiser, pointing instead to cascading failures or problems that allowed water intake. The boat Volare had three levels and carried 20 passengers.