It strikes me that, in order to survive something, you have to be there. So I'm guessing the 10.000 survivers are actually people that were on the planet at the time of destruction.
I'm guessing this is correct. You don't count people who weren't directly involved. For example, I've heard it said that about 15,000 people in the World Trade Center escaped before the towers collapsed on 9/11. If you were asked "How many people survived", would you limit your answer to the 15,000 who were actually there and escaped, or would you also include the nearly 7 billion of us who survived the event because we weren't even there?