Otherwise how can humanity completely lose their construction techniques that was globally known and spread?
We didnt lose anything. We have far better techniques now. It is like the myth that Roman's made better concrete. Just because we we often cheap out doesnt mean we cant.
I meant that the odds of such multiple desctructive events happening is such a short time frame are slimmer than a bigger happning just once.
We have seen such events over a far short time span, I think you are wrong. Natural disasters happen. Especially since the disasters those places had were common to their area.
