Detail this asset from Unity Store: Original Link
This is a paid asset, but now you can download Easy Destructible Wall Free.
Easy Destructible Wall v1.21
Adding a destructible wall into your game is now as simple as dragging and dropping. This pack contains three variations of the wall, ranging from twelve to almost a hundred rigidbodies.
The chunk based wall is compromised of multiple chunks, which are made out of several bricks. The chunks are shattered based on how much of a battering they receive.
All scripts are written in C# and are commented.
You can watch a video of it in action here or have a play here here