Building and digging while other parts of the base breaks down and destroys itself.

[War_Tornado]

Don't know if anyone else has had parts of your base that was previously solid just turn to crap. I do not make odd structures and my base is mostly concrete now. I started a new venture and dug deep (to the very bottom) and started to hollow out an area. When I was doing this, the upper structures of my base started to collapse. Mind you these structures have NOT ever done this before and have held back many zombie attacks, including numerous blood moon assaults. 

I initially made a 5x5 shaft all the way to the bottom. Started digging horizontally to open a space up. I had achieved a sizable room with some natural pillars (much like in Lord of the Rings movie scene in Moria). then it started happening a little by little, concrete blocks along with steel blocks collapsing in and around stable ground areas of the base. Some down low some up high structures.

 

Don't know what to make of it. Don't know if I should report it as a Bug, any thought....

[Javabean867]

That is to be expected.  You only have full stability if there is an unbroken line from block to bedrock.

 

And digging under a base can destabilize a block enough that it falls off you structure. 

[War_Tornado]

The location of the collapse was off to the side.