it's a mystery
A trio of Dutch scientists armed with hydraulic software and information about the tides have concluded that three men who famously escaped from Alcatraz in 1962 could have survived.
Prison officials and investigators at the time said that brothers John and Clarence Anglin and Frank Morris all died during the dangerous escape, but their bodies were never found. After simulating dozens of boat launches around Alcatraz at different times overnight, the scientists have determined that if the men left the island between 11 p.m. and midnight, they could have ended up on land north of the Golden Gate Bridge, but if they departed before 11 p.m., the currents would have been strong and carried them to certain death in the Pacific Ocean.
Team member Rolf Hut says he knows that this isn't definitive proof of survival, but "the latest and best hydraulic modeling information indicates that it was certainly possible."