Destroying GameController Respawns?

I've been having this problem for awhile now; it's the only thing stopping me from completing my android app.

I am respawning my sprite through a GameController, and it works perfectly. But, what I am having trouble with is destroying them. I want the player to be able to destroy the falling objects just by touching on. How do I do this?

Do I attach a box collider to the gameController or the Sprite Prefab?