The cloud was rising from a mountain – at such a distance we couldn’t tell which, but afterwards learned that it was Vesuvius. I can best describe its shape by likening it to a pine tree. It rose into the sky on a very long “trunk” from which spread some “branches.” I imagine it had been raised by a sudden blast, which then weakened, leaving the cloud unsupported so that its own weight caused it to spread sideways. Some of the cloud was white, in other parts there were dark patches of dirt and ash. … Broad sheets of flame were lighting up many parts of Vesuvius; their light and brightness were the more vivid for the darkness of the night… The buildings were being rocked by a series of strong tremors, and appeared to have come loose from their foundations and to be sliding this way and that. Outside, however, there was danger from the rocks that were coming down, light and fire-consumed as these bits of pumice were … It was daylight now elsewhere in the world, but there the darkness was darker and thicker than any night … Then came a smell of sulphur, announcing the flames, and the flames themselves.
– Pliny the Younger