The Dalek Empire detonated the Apocalypse Element within the galaxy, causing widespread destruction at eighteen light-years Gallifrey-relative and would be destroyed over six hours. However, the unpredictable nature of the element sped up the destruction, but the fireball was contained and kept from engulfing the universe through the use of the Eye of Harmony.
The Daleks launched two invasions of Mutter's Spiral from this galaxy 2,500 years apart. The Great Catastrophe didn't destroy all Dalek technology in the Seriphia Galaxy. (AUDIO: Dalek Empire I[which?], Dalek Empire II: Dalek War[which?], Dalek Empire III[which?], Dalek Empire IV: The Fearless[which?])