I had heard of the Birdman of Alcatraz. There was a film (based on a book by a prisoner, Robert Stroud who became something of an expert on birds). The film may have given something of a sanitised version of Mr Stroud's character because he had been a violent person before he was imprisoned at Alcatraz. That's not to do with the possibility of escape from Alcatraz though. On the balance of probabilities I think it's more likely that the escaping prisoners in the article cited by Dirk did drown but I would like to think that they were successful. I guess we'll never know unless either (a) remains were found which could be shown to belong to the escapees or (b) one of the prisoners were to confess on his deathbed and a test of his DNA could be performed after death.
Even DNA may have its limitations - I have insufficient scientific knowledge to speak in depth about DNA but I do remember nordmann saying something about the DNA tests done to "prove" that the skeleton in the carpark in Leicester belonging to Richard III (as in King of England) not being completely foolproof.