A new study— published in Current Biology by a team of researchers at Harvard University and the Archaeological Park of Pompeii in Naples, Italy—asserts that ancient DNA taken from some of the victims challenges stories long told about those particular Pompeii citizens.

In mere minutes, the giant cloud of ash and gases killed an estimated 2,000 people, many of whom were unearthed more than a thousand years later. Their decomposed bodies were preserved by the ash, and archaeologists were able to reconstruct their forms using plaster casts of the cavities they left behind. More than 100 casts have been made to date.

This new study probed the DNA evidence that has been taken from some of these bodies. The team used the same strontium isotopes that were used to date the DNA samples to get a better understanding of the diversity and origins of Pompeii’s residents.

A recent DNA study has upended long-held theories about the people who died in the ancient Roman city of Pompeii, revealing unexpected details about the demographics and connections among the victims.