Before the Alcatraz Federal Penitentiary opened in 1934, the US government called it "inescapable." In 1962, three inmates proved that theory false.
Alcatraz's Past
Triathletes travel from around the world every year to participate in the "Escape from Alcatraz" swim in the San Francisco Bay. Most people join this event just to prove their fitness, but some individuals take the plunge to see firsthand what it was like to escape from the world's most heavily guarded prison.
Nowadays...
Alcatraz isn't actually a functional prison facility anymore, partially because of the 1962 prison break that caused the Department of Defense to want to shut down the facility. Nobody knows exactly how the escape went down in the moment. But, it seems like the story of the inmate's experience likely didn't end with them drowning in the harbor...