After unlocking the door and dispatching a few ghouls....there is a door to the left about midway thru the tunnel where a Glowing one is crouched...
Killed the Glow Ghoul....went to go up the stairs into this area....and fell thru the floor, then respawned at the other end of the tunnel where I immediately set off some frag mines and died. Tried re-loading and jumping onto the stairs...as well as moving trash cans to use to jump onto the stairs....all to no avail.
Seems like there is no way to get into this area without falling thru the floor.
Please add this to the patch list!!!!