There is more to the story. The bus was incredibly strong, but failed to stop some disasters. It eventually came into a spiritual form in which it rose to the sky. It made heaven. Then one day it saw one of its creations, human, had become dominant. The humans who died were let into heaven with the bus. When a human was bad, it's soul was burnt and moulded into rocks or lava. After some time, this resulted in the creation of hell. From now on bad souls were simply sent to "hell" instead of becoming it. Millions of years passed. Humans became smarter. Enter the modern era.