In the TV series Future Boy Conan, a massive war left the Earth in shambles and humans tried to flee the planet on space ships, except they all failed except for one that managed to crash on an island that somehow survived the destruction. All of the survivors eventually died except for Conan, who was born after the space ship crashed, and his grandfather.
Then a girl named Lana washes up on shore and talks about this entire country of people. If the Earth was destroyed and all the other space ships didn't make it, where did these people come from?