One hundred prisoners attempted to escape Eastern State Penitentiary. Architect, John Haviland (1792 – 1852), did not design this prison to be capable of escape. The walls stand 30 feet high and 12 feet thick at the base. This horrifying structure that was designed to strike fear into anyone who views it, sits on 11 acres with its castle-like façade.

The most famous escape attempt from Eastern State Penitentiary happened in 1945. The mastermind behind the 12-man escape was Clarence “Kliney” Klinedinst. Kliney was imprisoned for burglary and forgery but while serving his sentence, he became a plasterer and stone mason. One of the walls that Clarence Klinedinst was working on even bears his initials to this day. When he was returned to his cell at night, he would sneak materials in and began digging through the walls of his cell. It took a year for the 12-man crew to dig the entire 100-foot tunnel beyond the walls and escape. They were quickly captured. The most notable man on the crew was bank robber “Slick Willie” Sutton.

Leo Callahan is the only man to ever successfully escape Eastern State Penitentiary. Charged with Assault and Battery with Intent To Kill, Callahan and five other inmates built a makeshift ladder that scaled the enormous walls. Five of the prisoners were caught. Leo Callahan is still at large, but he would be 110 years old.