When the Green Poison pandemic began to rapidly spread, all of the infected citizens were pushed into the middle of Manhattan while the government made attempts to discover a cure for the virus, this area quickly became known as "The Dark Zone."

Due to the high volume of rioting and looting within the walls, Martial Law was put into effect. The military were eventually forced out of the Dark Zone, leaving behind all of their equipment, and further increasing the dangerous activity within.

Subsections DZ01-DZ06 were being used to quarantine the sick; while DZ07-DZ09 were mostly used for dealing with the sheer amount of bodies that were falling due to the virus.

It's areas like this within DZ North that showcase raw enviornmental story-telling within the franchise. I often walk the streets in the DZ and find myself holding my breath at the overwhelming (and often unsettling) scenery.