Cavein, working as intended?

[bmjclark]

Not sure if its related but I just mined a supported tile and it caused a cave in of unsupported tiles outside its radius.

red is mined tile.

Edit: Area was previously open as part of natural cave.

Im guessing there used to be another support there and it prevented the cave in which caused the support to break.

[Granger]

Tiles supported by multiple supports should distribute the damage over all of them.
@jorb: not apply the whole damage to each one!