Alcatraz prided itself on being the most secure prison in the world. In 1939, it placed its most dangerous prisoners in the insecure D-Block. D-Block featured cells like this (photograph shows a typical A-Block cell). The square bars did not contain the tool-proof core which made them impervious to hacksaws. The lower risk prisoners in B and C blocks were penned by such bars. D-Block cells also had easilly picked locks. D-Block prisoners let themselves out of these old Army-era cells every night. It was a small matter for Henri Young and Rufus McCain to get out to do the preparatory work on the "tool-proof" window guards. After the 1939 breakout attempt, the bars in D-Block were replaced.
Photograph Copyright 1997 by Joel GAzis-SAx