Tiberian Spiral

The Tiberian spiral galaxy was a galaxy that what Porridge referred to as a "poor blighter" had blown up by pressing a button. This wiped out everything, including the Cybermen. It contained, according to Porridge, "a million star systems, a hundred million worlds" and "a billion trillion people." After its destruction, nothing of the galaxy was left, just a black, gaping hole in space. (TV: Nightmare in Silver)