User blog comment:Damous/Why Bioware has NOT betrayed us/@comment-857026-20120314031053

What I'm seeing all over the net is that a lot of players have deduced that the entire galaxy is destroyed in all three endings. This however is not the case, In arrival, the mass relay is composed of dark energy which in it's raw form was capable of destroying the entire system it was in.

However, the Prothean VI points out that the crucible allowed for dark energy transmissions, which likely means that the energy was converted; and the resulting explosions of synthetic destruction / control / synthesis energy affected synthetics/organics only while leaving planets and fauna alone.