I have thought about this for such a long time

Ep: 15 - Michonne attcks The Governeor like she did in the comics leaving him badley wounded but he survives. Ep: 16 - Merle walks in on him in the hospital and finishes him off. End of Season 3

During the first part of season 4 (5 - 8 episodes in) the prison attack begins and a lot of survives die during it Including Merle at the hands of Daryl

What are your opinions?