An end to the prison's operation was eventually brought about by the combination of a large number of factors: the increase in assaults and other types of violence; the turnover of officer personnel; the increase in the number of inexperienced officers; the general drop in officer morale; the pressure from a public concerned about the location of the prison; the pressure from critical penologists; and the vast deterioration of the prison's structure and surrounding facilities. On May 15, 1963, Alcatraz Island Prison was officially closed.
During its 28 years as a Federal Civil Penitentiary, Alcatraz experienced 14 escape attempts involving 39 inmates. Of the 39, 26 were quickly recaptured. Seven were shot to death by prison officers, and six were drowned or lost in the turbulent waters of the bay....Less then 1% of the total population of the Federal Prison System ever reached the island prison. At the close, the highest register number was 1041 Az.
-Alcatraz '46, The Anatomy of a Classic Prison Tragedy, Don DeNevi