Back to #2562 - Dan McClellan, with Dan McClellan.
How Small Did Toba Leave the Human Population?
Numerous enormous natural disasters have already hit. The Toba volcano knocked the human population down to a few thousand people, seventy plus thousand years ago, and the same kind of crash has happened a ton of times.
A later disaster could leave zero people, and survivors would have to start from scratch. A crash on the scale of Toba is super possible.