Unless this is a feature of storage, there was a weapon cache with a door/terminal that was generated without a door/path to access it. I discovered it by hacking Layout(Zone) and checked for a hidden entrance with Access(Emergency) on a nearby terminal. Both hacks were successful, but there was no apparent path to the walled off area.
Fortunately I had explosives with me
This was Beta 5 with the seed SuspensionCoilMagmablaster on level -9/Storage, right near the entrance point.