Year 2190 of the Old Calendar System, or Year 120 of the New Calendar, humanity's technology advanced by leaps and bound. While they encountered numerous crises enough to eradicate all of humanity, all beings even, at earth, they managed to pull through.
Year 0 of the New Calendar, ever since then, nothing is ever the same. The “Great Devastation”, a great earthquake at the world scale, occurred.
It wiped out all civilization and a half of the human population. All that's left is rubbles and the remaining humans, tasked to build their civilization from scratch.
And they succeeded! They're much more prosperous than before. But soon they noticed that the world isn't what it once been.
This time, surely, they will survive?