"the year twitter died" is passive, and generally not a preferred way to write this, as there are specific actions by one (EM) or several individuals. The active phrase, "the year twitter was killed", is more reflective of the actual situation, and thus better communication. FTFY.
but this is the news, and as much fun as it might be to point fingers, that could get the office in trouble. Better to just use the passive voice, avoid ruffling any feathers, and maintain neutrality. AP style guide says their headline is fine.