[trackercowe]

You can't leave Lizzie alive and have her be around the baby. The minute they turned their backs on her she probably would have either killed Judith to see if she turned, or fed it to a walker. I know Lizzie was still a child, but I think at this point she was pretty much beyond help in that environment. She took the life of her sister, even though Carol did everything in her power to explain to her the reality of the situation they were facing these past few months. Sure children that young can be rehabilitated, but in that environment it just wasn't worth the risk.

It's kind of strange that now everyone that came from Woodbury at the end of last season is now dead. It sort of parallels the tail section from Lost in a way, in that in the end bringing in this new group played such a small role in the series. Kind of makes much of last season seem somewhat pointless in a way. At least someone from the tail section did survive the entire series of Lost (he just didn't do a whole lot).

It was pretty much the Old Yeller situation, where Lizzie was rabid and needed to be put down.