어 버리다

goes and does it completely

Marks the action as finished off entirely, and colours it with how the speaker feels about that. Usually it is regret or annoyance — the camera broke, I've lost two already, the driver went and developed a mind of his own. Just as often it is relief or satisfaction at something being wiped away, as in wishing all the world's trash would just get blown off and all the illnesses would vanish. Plain past tense states the fact; this adds the "and that was that".

Register: casual and emotive