I think prior collapses of civilisations, most notably that of the (Western) Roman Empire and the Classic Maya (Tikal vs. Calacmul) give an example. But there is also a more recent occurence that I think is comparable. Look at this photo:

We discussed this before. The populat perception of the end of the Western Roman Empire is coloured by the influence of British historians and the fact that in the British Isles urban civilisation went away with the Roman Legions. In Hispania, the very romanized Visigoths simply took over the Roman provinces. So your mileage may vary.

Oye, vatos, dees English sink todos mi ships, chinga sus madres, so escuche: el fleet es ahora refloated, OK? — The War Nerd