The lunar orbit has changed and the moon is about to fall down. The tidal force has now a huge effect on the ocean which has destroyed almost all terrestrial life. Every day, the sea level rises and lowers by hundreds of meters.

But the moon won't survive very long. At some point, the stronger tidal force created by Earth will crack the moon's crust centuries before the actual collision. The deformation will break the moon into countless scattered fragments, and the sea level will then stabilize. During the impact, it is going to rain rocks and dust for decades, but life will go on on a new ground.

I have been told that it is not the first time such an event occurs.