A mass grave that could hold up to nearly 800 infants and young children is being excavated on the grounds of the former home run by the Bon Secours Sisters, an order of nuns.

The burial site has forced Ireland and the Catholic Church to reckon with a legacy of having shunned unmarried mothers and separated them from their children. The grave was accidentally discovered by two boys half a century ago; but the horror was unknown till a local historian began digging into the home’s history.

Irish historian Catherine Corless revealed that the site was atop a septic tank and that 796 deceased infants were unaccounted for. Her findings caused a scandal when the international news media wrote about her work in 2014.