Short answers, pulled from the story.
Mount Vesuvius erupted on the 24th or the 25th of October 79 AD, according to a collaborative study from 2022. The city was buried under up to six metres of volcanic ash and pumice over two days, with pyroclastic flows reaching temperatures of at least 250 degrees Celsius causing instant death even for people sheltered inside buildings.
Pompeii had a population of approximately 20,000 by 79 AD, though more recent estimates based on household counts suggest a figure closer to 11,000-11,500. The city covered an area of 64 to 67 hectares.
Architect Domenico Fontana encountered ancient walls while digging an aqueduct in 1592 but kept the discovery secret. Major excavations began in 1748 after Herculaneum's rediscovery in 1738 prompted Roque Joaquin de Alcubierre to dig at the Pompeii site. The city was formally identified by an inscription found on the 20th of August 1763.
Giuseppe Fiorelli, who took charge of excavations in 1863, devised the technique of injecting plaster into the voids left by decomposed bodies in the ash layer to recreate their forms. Today, clear resin is used instead of plaster because it is more durable and preserves the bones for further analysis.
A collaborative study in 2022 determined the eruption date as the 24th or the 25th of October 79 AD. Supporting evidence includes a charcoal inscription found in 2018 with a date of the 17th of October, heavier clothing on victims, autumn fruits in the shops, sealed wine fermentation jars, and a coin minted no earlier than the second week of September.
Since 2018, excavations in previously unexplored areas have found harnessed horses in the Villa of the Mysteries, the remains of two men including a probable slave in Regio V, a thermopolium with food still in its pots, a bridal chariot called a pilentum, the tomb of freed slave Marcus Venerius Secundio, and a dining hall with rare frescoes depicting Helen of Troy and Apollo with Princess Cassandra.