I for one welcome our new explosively burrowing bunker buster smart bomb overlords.

[substitute]

Deep digger falls out of the sky, sticks in the ground, and then uses a cannon to chew through concrete before it explodes. It can grind through at least 10 meters of concrete while reporting its progress and coordinating with other burrow bombs to meet and greet and blow up.

I think it's behind me right now.