Always lots to see at the West Burnaby Nonspecific Sickhouse.

There is a kind of utility tunnel system connecting some of the buildings, it seems. I found an entrance into one of these. It wasn't very comfortable: I had to get down on my haunches and waddle through it.

Here's a picture of the tiniest (< 3 feet high) fire door (sign reads "Fire Door, Keep Closed"):

I emerged, down a ladder, into a kind of machine shop room, which had another tunnel opening, and a normal-sized exit to the "Tunnel" level hallway that runs underneath the hospital. Lots of opportunities for exploring there for the intrepid.