Dio Cassius, Roman History 66.23.2-3
We all know Pliny’s letters to Tacitus offering an eyewitness account of the eruption of Vesuvius, but Dio’s version is also well worth a read. Unfortunately it’s in one of the books of Dio which only survives in a “Reader’s Digest” version or “epitome”.
καὶ διὰ ταῦτ’ ἔφυγον οἱ μὲν ἐκ τῶν οἰκιῶν ἐς τὰς ὁδοὺς οἱ δὲ ἔξωθεν εἴσω, ἔκ τε τῆς θαλάσσης ἐς τὴν γῆν καὶ ἐξ ἐκείνης ἐς τὴν θάλασσαν, οἷα τεταραγμένοι καὶ πᾶν τὸ ἀπὸ σφῶν ἀπὸν ἀσφαλέστερον τοῦ παρόντος ἡγούμενοι. ταῦτά τε ἅμα ἐγίγνετο, καὶ τέφρα ἀμύθητος ἀνεφυσήθη καὶ τήν τε γῆν τήν τε θάλασσαν καὶ τὸν ἀέρα πάντα κατέσχε, καὶ πολλὰ μὲν καὶ ἄλλα, ὥς που καὶ ἔτυχε, καὶ ἀνθρώποις καὶ χώραις καὶ βοσκήμασιν ἐλυμήνατο, τοὺς δὲ δὴ ἰχθύας τά τε ὄρνεα πάντα διέφθειρε, καὶ προσέτι καὶ πὸλεις δύο ὅλας, τό τε Ἑρκουλάνεον καὶ τοὺς Πομπηίους, ἐν θεάτρῳ τοῦ ὁμίλου αὐτῆς καθημένου, κατέχωσε.
And for this reason they fled, some from the houses into the streets, others from outside into the houses, from the sea to the land and from the land to the sea; they were so confused that they thought every place where they were not was safer than where they were. While these things were happening an untold amount of ash was blown out: it covered both sea and land and filled the whole air. It did many other injuries, as it chanced, to humans, to farms, and to cattle. Indeed it destroyed all fishes and birds, and moreover it buried two cities whole, Herculaneum and Pompeii, while its population was sitting in the theatre.