55 years later, Alcatraz prison escape remains a mystery

SA boat passes Alcatraz Island on April 7, 2011 in San Francisco, United States. Justin Sullivan / Getty Images
SAN FRANCISCO — Alcatraz was a federal penitentiary for nearly three decades. During that time, there were 36 escape attempts: 23 were caught, six were shot and killed, and two drowned. But three men — brothers John and Clarence Anglin and Frank Morris — have never been found, CBS San Francisco reports.
Fifty-five years ago in June, they pulled off one of the greatest