A horse recently found trapped in the ashes of a suburban Pompeii villa was just the tip of the equestrian iceberg. Since that discovery was announced last week, archaeologists have revealed that at least three horses perished in the villa's stable during the volcanic eruption of Vesuvius that famously buried the ancient Roman town.

At least two of the animals were harnessed and possibly prepared for a frantic evacuation when they were hit with the lethal, pyroclastic flows that rushed through Pompeii and its surroundings after midnight in the summer of A.D. 79.

The stunning, complete plaster cast of one of the villa's horses is the first of its kind from Pompeii. When the volcano erupted, many of the town’s residents and animals collapsed and died in place after being struck with waves of superheated poisonous gas and ash. Their decaying bodies then left hauntingly shaped voids in the hardened ash layer.

Watch: Horses Found in Pompeii May Have Been Harnessed to Flee Eruption

In the late 19th century, archaeologists developed a method of injecting plaster into these voids to capture more details about the dead. Since then, it’s mostly been used on humans—and an infamous chained dog—but this was the first attempt on a large mammal.

The team also cast two legs from another horse discovered nearby, but the rest of the void left by that body had been destroyed by tomb robbers, known locally as tombaroli, who were tunneling around of the walls of the ancient villa to steal artifacts they could sell on the black market.

The void and skeletal remains of a third horse were also almost completely destroyed by tombaroli, zooarchaeologist Chiara Corbino, who studied the horses, tells National Geographic.

Evidence for bits and bridles around the two cast horses suggests that they were harnessed by people trying to flee the eruption, says Massimo Osanna, general director of the Archaeological Park of Pompeii. The remains of the third horse are too incomplete to determine whether it was also harnessed at the time of death, says Corbino.

Operation Artemis

The villa, located in the Civita Giuliana area outside the walls of ancient Pompeii, was originally discovered at the beginning of the 20th century, then partially excavated in the 1950s and later sealed. Investigators spotted the tombaroli tunnels last summer and alerted archaeologists from the Archaeological Park of Pompeii, who then excavated the previously unknown stable area.

View Images Evidence for a leather bit and bridle decorated with metal ornaments was found around the head of the horse. Photograph Courtesy of Archaeological Park of Pompeii

Italian authorities have since confirmed to National Geographic that the find is the result of a significant criminal investigation known as Operazione Artemide (Operation Artemis), led by Italy's national gendarmerie, the Carabinieri. This multi-year investigation took off in 2014, after thieves stole a frescoed depiction of Artemis, the Greek goddess of the hunt, from the walls of an ancient Pompeiian house that is currently closed to the public.

By early 2015, the operation had swept up more than 140 suspects—tombaroli, illegal art dealers, and even some mafia members—in simultaneous dawn raids across 22 Italian provinces. Teams recovered some 2,000 ancient artifacts, including illegally excavated vases, coins, and architectural fragments.