User blog comment:The Milkman/Extended Expectations, Part II/@comment-4939034-20120628162507/@comment-1440333-20120629140013

I don't know why people focus so much on the breath scene. For starters it may simply be Shepard's last breath. Secondly the reason the breath scene is there is simply because it is the only ending Shepard can possibly survive. In Synthesis and Control Shepard dies, sacrificing himself so that he can make the changes necessary. In Destroy however Shepard is merely caught in an explosion, the Crucible does not change him and so he gets trapped in rubble. That's all.