While Pompeii was incinerated by volcanic cinders, a minimum of 20 m (65 ft) of ash and mud swamped Herculaneum, hardening and covering the houses in a protective crust that kept upper stories and even some of the woodwork intact.
371439
The city of Pompeii was destroyed by a volcano.
371440
The mud and ash that flooded Herculaneum destroyed everything and protected nothing.