[W|0.12.914] Thick roofs support each other when near each other

[SuperRedNova]

Circumstances: I was Mining away part of a mountain near by base when I found two thick roofs next to each other.  I then tried to mine away the collapsed rocks.
What happened: When one collapsed rock was mined away, it just collapsed again in the same spot. I have tried mining both collapsed rocks from the thick roofs around 5 times or so an they are still re-collapsing.
What I expected to happen: I expected the collapsed rocks to just go away once they were mined.

The two stated thick roofs/collapsed rocks can be found to the right of my right most solar panels at my base in this save file here: https://drive.google.com/file/d/0B7BKPvw76FQRdmpEZXB2bkN2TVE/view?usp=sharing

[Bohb Daishi]

It has been my experience that the thick roofs will collapse indefinitely. This probably occurs by design.

[TLHeart]

You will never be able to remove those two spots. The mountain will just keep collapsing. 

Makes perfect sense inside a mountain, but since we have no visual of what is above, it does look very strange in your game.

[ison]

Working as intended. Locking.