:’) Pliny the Elder was an admiral I think, anyway, he was or at least felt responsible for the safe evacuation, went ashore, and may have succumbed to a wave of poisonous fumes rolling down from Vesuvius. Those with him ran for their lives. Seems like the eyewitness report was written by Pliny the Younger? Dunno.
Correct. Pliny the Younger, an eye witness to the eruption wrote of the events in a letter to Tacitus at the request of Tacitus. We do not have the original request, nor any work of Tacitus were Pliny's research was used.
Pliny's' uncle, the Elder Pliny was Admiral of the Roman fleet, launched rescue operations and died in the attempt. A heavy asthmatic, he was overcome by the fumes and died.