User blog:JordanaBrewsterFAN/The Citadel: Destroyed or not?

I have a questio whi may be a little stupid but I'd like to know. I have seen all three endings (with Extended Cut) and I was wondering. Why is it that in the Destroy and Synthesis endings the Citadel is destroyed but in the Contron ending it remains intact? I found one solution for the Destroy ending. The energy is meant to destroy synthetic (robots whatever) and that is why both the citadel and mass relays were destroyed but what about in the Synthesis ending? Does anyone know?