[jsinton]

Yea, sounds like you broke the porcelain. There was a rubber doo-hickey around the bottom of the spark plug wire which seals around the porcelain. Find something like needle nose pliers to reach down in there and clean out the broken pieces of porcelain and the rubber washer thing. The threads and the metal part of the plug should still be there, and you should still get your socket on it and turn it. I find it hard to believe you broke the metal bottom of a spark plug. Maybe you rounded it off, but this is also unlikely. You never got you spark plug wrench all the way to the bottom.