Well, I still say there was a second gunman.
Heads up, people. Pliny the Elder and Younger are huge figures of history.
The elder was a scholar, whose hard work and intelligence elevated him in Roman ranks to the equivalent rank of Admiral. When Vesuvius erupted, his fleet was anchored some distance away. People had no idea what was happening, but his extensive travels had taken him to Etna and he knew about “fire mountains”. He ordered the fleet to set sail for Pompeii and Herculanium, because he was a decent guy and had balls.
They sent boats ashore to rescue people. He led the effort, again because he was a decent guy. He got a lot of people out, but he was ashore when the vertical pyroclastic column collapsed and spread outwards. It killed him, mostly via gases rather than outright heat.
Several miles offshore was an island with his sister and nephew (as I recall, not his son) on it. The Elder had taught the Younger to read and write, which automatically made him significantly elevated in Roman society.
The days of eruption went on the the Younger kept a careful journal of what he was seeing on the mountain. Days of eruption had coated the sea with pumice, which floated. When the column collapsed, the gases and heat walked across the floating pumice and came for the island the Younger and his mom were on. He grabbed his writings and his mom and they sprinted to the other side of island. They survived.
His description of the eruption was so precise and useful for thousands of years afterwards that the Vesuvius type of eruption is called a Plinian after him.