When asked in a interview with Collider.com if the show The Walking Dead television show could survive if all of the original characters were killed producers Robert Kirkman and Glen Mazzara had some interesting things to say.
"I honestly do think that the show could survive. Telling stories in this world is an interesting prospect. To a certain extent, this is Rick's story, so something really drastic would have to happen for it to suddenly shift gears, and that might be somewhat jarring. I've always said that this is a very dangerous world that we're telling stories in and, if characters aren't dropping like flies and dying left and right, we just wouldn't be telling a realistic story. So, in an effort to keep things realistic, we are going to be burning through cast, like we have been in the first two seasons. It is an evolving show, and I really like the fact that the cast is cycling. When I see these big marketing images before every season, it's like, 'Here's the cast,' and then the next year, it's like, 'Here's the cast,' and it's always pretty different. I just think that's cool. It shows that you're getting something new this season, which I think is really exciting."
"One of the things we take seriously is the issue of life and death in this season, and what that means for the survivors. So, I do think that the show could suffer any death and still continue. I would never want to have everybody wiped out and come back with a brand new cast. That's a little crazy. We would never do that. But, you show how people survive each other's death and what that means and what that loss is. This is a show that's very much dealing with that."