No prisoners are believed to have ever successfully escaped from The Rock--the heavily fortified Federal prison on Alcatraz Island in San Francisco Bay. During its three decades of operation (1934-1963), only three men ever made it off the island; officially, they were believed to have been drowned in the cold waters following their escape, and their bodies were never found nor their whereabouts determined. This escape, on which the Clint Eastwood film, Escape from Alcatraz (1979), was based, included three inmates: Frank Morris and the Anglin Brothers--John and Clarence. It has been described as one of the most intricate escapes in prison history. Using makeshift tools, the trio chiseled through the concrete wall into an air vent leading to a small corridor and on to a fan vent. They used papier mache dummies (with human hair attached) to place in their beds and stolen raincoats to construct their rubber rafts. Some of their items were later found on nearby Angel Island, but the official report is that the three men drowned in San Francisco Bay. The ending of the Clint Eastwood movie provides a different possibility; and a later reenactment by the TV show Mythbusters also concluded that the three men could have succeeded in escaping.
If they indeed escaped, Morris and the Anglin Brothers were able to accomplish something that some of the most famed criminals in American history could not. Inmates at Alcatraz included Al Capone; George "Machine Gun" Kelly; gangsters Al Karpis and Doc Barker of the Ma Barker Gang; Mafia boss Whitey Bulger; Harlem godfather Bumpy Johnson; California gangster Mickey Cohen; and Richard Stroud, the "Birdman of Alcatraz."
BTW, the two Anglin brothers have supposedly been spotted several times over the years in their home town of Ruskin, Florida. A local TV station recently attempted to interview family members with no luck. The brothers were seen, according to local legend, at the funeral of a family member--dressed in women's clothing. The Anglins were excellent swimmers as youths, taking daily plunges into the Little Manatee River; thus, the belief of local residents that the Anglin boys could have easily survived the swim from Alcatraz to the mainland.