THE ESCAPE ROUTES
As you can see above,
the flooded cavern that all the catacombs intersect, lies directly beneath
the main entryway of the Asylum, and serves as the launching point for
everyone's escape. The night they escaped, at least some of the
prisoners went to the main entryway above ground before retreating below.
It would have been much easier to just go directly below ground rather
than stopping in the entryway where many guards would have had a chance
to spot them. Though these inmates are barmy, I do not believe
they are stupid. I believe there must have been a reason for their
stopping above ground.