I had built a house and far into building it, the roof ended up touching with two blocks of an existing tree standing next to it.
A couple minutes later, I chopped down one of the wooden blocks in my house's wall (misplaced a block) and thar she went,
my entire second floor decided to fall down like a tree.

Most notably, the tree itself still stands.

The structure that fell was an interconnected skeleton for the second floor of a house, made up entirely out of spruce logs. (not planks)
The tree (that still stands), is an oak tree. (this might explain why the tree didn't fall)

To make sure this was the case, I rebuilt the second floor without touching the tree and chopped down several blocks, no issue there.
The structure must touch the tree (& maybe must be built out of strictly logs?)

Didn't see a single post / bug about this, so wanted to inform you.
(Wanted to post in your discord, but I dont have permissions to give bug reports out of the box)