During its nearly 30 years of operation (from 1934 to 1963), the federal prison on Alcatraz Island in San Francisco Bay housed some of America’s most notorious felons, including gangsters Al “Scarface” Capone and murderer Robert Stroud, the famous “Birdman of Alcatraz.” Dubbed “the Rock,” Alcatraz was known as the nation’s most secure prison, and federal officials insist that not a single inmate ever successfully escaped from within its walls. But is this really true?