Building game block separation

Hi, i made a sandbox building game, i've made it so that when you left click, you create a block, when you right click, you delete a block.

Now, i want to make it so that if you delete a block joining two pieces together, those pieces separate and use their own rigidbodies.

For example this 3D piece: https://imgur.com/a/6U4N1Rp If you delete the center block, i want all pieces not connected become their own rigidbodies. How can i achieve this?