Rockfall at the Mine!

So, I found out something really werid today at the Mine, in one corner there's this really strange rockfall where it seems as if the rocks opened a crack in the wall or something. I'm guessing it's something for the new mission you know, like Herbert having an underground hiding place or a secret lab where he plans his next attack or something similar. Go check it out if you want and coment if you have any ideas of what it might be!