The stairwell at the Jason Farms lab runs two flights from the first underground level (Level 1) down to the lowest underground level (Level 3). The doors leading out of the stairwells are unlocked on Levels 2 and 3, but a security keycard is needed to access Level 1. The stairwell does not lead to an exit above ground.
To return to the floor plan of the Jason Farms laboratory, click here.