Alcatraz Federal Penitentiary and the island became a prison of the Federal Bureau of Prisons in August 1934 after the buildings were modernized to meet the requirements of a top-notch security prison. Given this high security and the location of Alcatraz in the cold waters and strong currents of San Francisco Bay, the prison operators believed Alcatraz to be escape-proof and America's strongest prison. Alcatraz was designed to hold prisoners who continuously caused trouble at other federal prisons. One of the world's most notorious and best known prisons over the years, Alcatraz housed some 1,576 of America's most ruthless criminals including Al Capone,
Battle of Alcatraz cellblock. Joe Cretzer was a west coast gangster and member of the Cretzer-Kyle Gang. In 1940 he was sentenced to 25 years for murder. After two escape attempts in the first months of his incarceration, one of which resulted in another murder charge, he was transferred to Alcatraz. In May 1941, Cretzer, Shockley and two other convicts made an escape attempt from one of the prison's workshops. Carnes was the youngest prisoner to reside at Alcatraz, having been convicted of murder in 1943 at the age of 16. He made a number of escape attempts and by 1946, when he