Tuam, Ireland - "Everyone knew there was babies buried here, but we thought it was only a small few," says James Mannion, a resident of this western town.

Camera crews and satellite vans assemble in the middle of a housing estate in Tuam. Mannion and other locals have come down to have a look. All are focused on a walled-in, grassy area the size of a basketball court.

Catherine Corless, a local historian, thinks there are 796 babies buried here, not including stillborns.

The site is on the former grounds of the Tuam Mother and Baby Home, which was owned by the Bon Secours nuns and was in operation from 1925 to 1961. This was one of several institutions funded by the state and run by the Catholic clergy to accommodate unmarried mothers - the "untouchables" of Irish life.

Unwed mothers brought their families great shame at a time when the Catholic Church's influence over society was strong, and children born out of wedlock who died often did not receive a Christian burial.

At the institutions, mother and child were separated after nursing, and the children fostered out or, sometimes, sold to prosperous American families. Meanwhile, the mothers stayed to work off their "debts". Some escaped to England. They risked arrest if they returned.

Corless remembers the home from her childhood. It was surrounded by 2.4-metre high walls topped with broken bottle caps. There were "home babies" in her school too, kept to "one side of the classroom, arriving and leaving at different times so there would be no interaction with 'ordinary' schoolgirls".

In 2010, she began to collect testimonies from former residents. Their conditions were miserable. They were fed little more than slops, and illness was rife.

Crowding and 'constant sickness'

JP Rodgers has also come down to Tuam to see what the fuss is about. He grew up in the home. His mother came from a poor family and, according to her son, she was arrested for begging when she was just two-and-a-half-years old.

As a result she had spent her own childhood in an industrial school. When she left to work in a "big house" at the age of 16, she was "taken advantage of", he said. She was placed in the Bon Secours home and they were separated when he was 13-months old.

I know there were measles epidemics at points, but the number is unbelievable. In one year alone, 57 children died aged between one month and three years. - Catherine Corliss, local historian

His memories of the home are few, though he remembers the crowding and the "constant sickness". He stayed on until he was five-years old, when he was fostered by a family whom he says were unkind to him.

After three years of gathering testimony, Corless applied to the state registration office for information about the number of baby deaths that had taken place there. She was told that 796 had died.

"I couldn't believe it was that many. I know there were measles epidemics at points, but the number is unbelievable. In one year alone, 57 children died aged between one month and three years."

Her next step was to seek the location of the bodies. None of the babies' names appeared in local graveyards.

As the products of "sin", these babies weren't buried alongside others. Mothers didn't attend their baptisms. Instead, the "mother" listed on most of the baptism certificates is Bina Rabitte, an assistant matron.

Eventually, Corless concluded that they must be buried in an area close to the home, which she thinks was also the site of a defunct septic tank. In 1975, two schoolboys had discovered "small skulls" on the site. It had been covered over and seeded and local people had tended it for years.

Although Corless and a group of local people sent out a press release seeking funding to build a proper memorial, there was little response. "We expected an influx of shock and horror," she said. "We thought it would be front-page news."

Story goes 'ballistic'

Months later, the story was reported by an Irish newspaper, and outrage erupted on social media. Now, international coverage has caused the story to "go ballistic", said Corless' husband, who handled the phone at their home outside Tuam while she was being interviewed by a Danish TV crew.

Corless is shaken by the time she returns. It is afternoon and she still hasn't eaten. She's barely slept in recent days.

The causes of the babies' deaths have only been confirmed for 50 cases. They include measles, gastroenteritis, chicken pox, whooping cough, abscesses of the scalp, laryngitis, tuberculosis and extreme malnutrition.

A shrine is set up at the site of a mass grave of up to 800 children in Tuam County, Galway, in western Ireland [EPA]

The obvious next step would be to order an excavation. Last week the police said they had already looked, though Corless said they had searched in a different place.

The septic tank may have garnered headlines, but the broader story goes beyond Tuam.

Newly released archive material from the Dublin Archdiocese shows that mortality rates in Tuam were either matched or exceeded by homes elsewhere in the country. Pelletstown in Cabra, Sean Ross Abbey in Roscrea, and Bessborough in Cork had death rates of up to one-third of their population in 1933.

Full statutory inquiry

"If something happened in Tuam, it probably happened in other mother-and-baby homes around the country," Archbishop of Dublin Diarmuid Martin told national broadcaster RTE.

"All the indications are that those who were running the institutions didn't understand, or did not want to understand, how you looked after children and how you examined the special care children needed at that early stage."

Evidence has also emerged that children in these homes were used for medical testing, and that their bodies were sold for dissections to medical schools. Poorer families were reportedly subject to worse neglect at the institutions.

The Irish government has just announced a full statutory inquiry into what went on in these Catholic Church-run homes.

Meanwhile, Corless continues to be in contact with many of the babies' relatives. Like many abuse victims, they have internalised their experiences and are often hesitant to identify themselves.

"I had an 80-year-old woman from England who told me terrible things, but then begged me never to use her name. They're ashamed. They still blame themselves," Corless said.