No Escape
Alcatraz Island held some of the worst American criminals during its time, such as Al Capone, Machine Gun Kelly, and Morton Sobell. The design of Alcatraz was the reason behind why they shipped all of the worst criminals to the San Francisco Bay.
The island was pretty much inescapable, crowded with high fences, gun towers, in addition to the island being over a mile away from land, was the reasoning people believed escape was nearly impossible. Although many believed this feat to be impossible, many prisoners still attempted to escape, with almost all of their attempts failing.