This project has moved to Planet Minecraft.
This data pack adds a configurable chance that natural stones will collapse in randomly shaped chunks when you go mining, to make mining more dangerous and exciting. Pickaxes enchanted with Unbreaking lessens the chance of a cave in, and higher levels of Unbreaking decrease the chance further.
This data pack supports all stone types added by my Underground Overhaul data pack.
By default, there is a 20% chance that stone and cobblestone in the Overworld, below sea level (Y=63), will collapse when mined, and a 20% chance that netherrack in the Nether will collapse when mined. Each collapsing block has a 50% chance to collapse each adjacent natural stone type block, but the maximum number of blocks that can collapse at once is 16. If you'd like to change these settings, you can find the configuration file at "data\cave_collapse\functions\config.mcfunction" within the zip file of the data pack. There is also a feature that allows end stone in the End to collapse when mined, but this is disabled by default.
More information about data packs and how to use them can be found on the official Minecraft Wiki.