The survivors have barricaded themselves in and are waiting for rescue. Imagine a zombie movie where zombies have infiltrated a house, but somebody has locked themselves in the closet.
Originally, I was going to have such survivors slowly turn into zombies as the game progressed (they were found and bitten) so you'd stop finding more survivors after a while. I later decided that was too evil.
The survivors have barricaded themselves in and are waiting for rescue. Imagine a zombie movie where zombies have infiltrated a house, but somebody has locked themselves in the closet. Originally, I was going to have such survivors slowly turn into zombies as the game progressed (they were found and bitten) so you'd stop finding more survivors after a while. I later decided that was too evil.