concrete issues

We had our first shot at taking out the floor of the fish pond today. We borrowed Tom's father's drill with a big concrete drill bit. The bit went in relatively easily for about three inches, then just stopped. We tried two other holes but the same thing. No dirt, the drill just stopped going in any farther.

Makes me wonder what's under the concrete that's stopping the drill. But it looks like we're going to need something more powerful from the tool hire place.