To the shoppers scrutinising the racks of newly arrived spring lingerie on the ground floor of the Monoprix store on the busy Boulevard Sebastopol, there was little to suggest anything unusual.

As they queued for baguettes, croissants and loaves at the boulangerie counter – also on the ground floor – most were blissfully unaware that a few metres below them archaeologists were brushing away centuries of sand and dirt to reveal hundreds of skeletons in a series of mass graves.

“It’s rather a bizarre thought,” Pierre, a retired civil servant, told the Guardian as he clutched his bread stick on Monday. “Still, there’s all sorts of odd things buried under Paris.”

Others in the queue at the nearby tills shrugged and carried on shopping uninterested in digging a little deeper into the story that had become le fait divers (miscellaneous news item) of the week.

At the last count the remains of at least 200 people have been uncovered under the shop floor, and experts believe there may be more, victims of a sudden and devastating disease or catastrophe.

The discovery was made when the store applied to convert part of its cellar for extra storage space.

Knowing that the building sat on the site of a hospital dating back to the middle ages, managers called in archaeologists to check for human remains. Nobody expected them to find much; most of the bodies buried in the hospital grounds had been disinterred when the building was destroyed in the early 19th century. Their bones were moved to the Paris catacombs, the underground ossuaries that hold the remains of about six million people in caverns and tunnels.

But as the archaeological team dug a little deeper, they were astonished to find dozens and dozens of skeletons in what appeared to be a series of mass graves.

“We had expected to find a few human remains as we knew it was a former hospital cemetery, but nothing like as many as we have found. We’ve come across hospital cemeteries before, notably in Marseilles and Troyes, but it’s the first discovery of its kind in Paris,” said Solène Bonleu of France’s Institute of Preventative Archeological Research (Inrap).

Eight mass graves have been found so far, seven of them containing between five and 20 individual human remains buried up to five deep within a 100 metre sq area. The eighth grave contained, at the last count, the remains of 150 bodies.



Isabelle Abadie who is leading the dig said there was possibly another layer of bodies below those that had been uncovered.



“What is astonishing is that the bodies were not thrown in, but put there with care and in an organised way. The individuals – men, women and children, were placed head-to-toe, no doubt to save space.



“It suggests there were a lot of sudden deaths, but we still have to find the cause of this sudden fatal event and whether it was an epidemic, fever, famine.”



The archaeologists have two weeks to complete the dig and allow Monoprix to convert its cellars.



“Eventually all of the bones will be removed, but we only have two weeks to finish the work so we’re not allowing people down there,” Bonleu said.



Scientists are carbon dating the remains and are carrying out DNA tests to establish how the people died. Paris was struck by the b ubonic plague in the 14th, 15th and 16th centuries followed by a devastating outbreak of smallpox in the 17th century. Epidemics were punctuated by repeated flooding from the river Seine and famines that also claimed thousands of lives.

In a statement, Inrap said: “The big communal grave, which we have yet to establish the exact size, seems to correspond to a wave of deaths the cause of which we don’t yet know. Adults (men and women of all ages) and children are there.



“The bones don’t show any lesions allowing us to determine the cause of such a mass of deaths.”



Many of the skeletons, well preserved in the sand, have their arms crossed over their chests, leading experts to believe they may have been wrapped in cloth.

The Hôpital de la Trinité was built in 1202 and was originally called Hôpital de la Croix de la Reine. It was run by monks and served to treat the poor and offer hospitality to pilgrims from the north who arrived at night after the city gates had closed. In 1353, the administrators allowed part of the land around the hospital to be used as a cemetery.



In the mid-16th century, part of the hospital became an orphanage known as the Hospice des Engants-Bleus, where residents dressed in blue uniforms learned a trade. The hospital and orphanage were closed during the French revolution and later sold. The buildings were demolished by private owners in 1817.

Officials have said the authorities will have to find a site to rebury the remains after they have been examined.

“It’s the state’s responsibility to find a place. They will be treated with respect,” Jean-Pascal Lanuit, head of cultural affairs in the Ile-de-France region that covers Paris said.