Story highlights More than 200 skeletons found under Monoprix grocery store

The store is on a site where a hospital cemetery was located, dating to 12th century

(CNN) Workers digging underneath a Paris supermarket have made an unsettling discovery: as many as 200 skeletons.

The grocery store, Monoprix, was doing some renovations in January and workers removing an underground wall discovered the bones. The area was apparently part of a cemetery for the Hospital of the Trinity, according to CNN affiliate, France's BFM-TV . The cemetery operated from the 12th century to around the 17th century.

Researchers and archeologists are conducting carbon dating and DNA testing to try to figure out when and why the people died, the affiliate said. It's clear they all died around the same time, lead archeologist Isabelle Abadie told BFM-TV, because of the way the bodies were neatly arranged.

"What's surprising is the bodies were not thrown in (the graves) but were carefully placed there in an organized manner. The individuals, men, women, and children, were placed head-to-toe," to fit as many as possible in the grave, Abadie explained.

A team of archeologists sifts through dirt to unearth centuries-old skeletons under a Paris supermarket.

Paris suffered several plague epidemics during the times that the hospital was in operation, as well as a smallpox outbreak in the 17th century.

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