A first-of-its-kind federal study of Native American boarding schools released Wednesday has identified at least 53 associated burial sites with 500 deaths reported so far, a number the US government believes could grow exponentially as the research continues.

“Each of those children is a missing family member,” said Interior Department Secretary Deb Haaland in a statement. “A person who was not able to live out their purpose on this earth because they lost their lives as part of this terrible system.”

The report by the Interior Department pinpointed more than 400 schools designated to assimilate Indigenous children into white society.

The investigation shows the schools operated for 150 years, starting in the early 19th century, which coincided with the removal of many Native American tribes from their ancestral lands.

The dark history of Indigenous boarding schools included taking children from their families and prohibiting them from speaking their Native American languages.

The schools also deployed “systematic militarized and identity-alteration methodologies,” including renaming children with English names, cutting their hair short, and forcing children to perform manual labor.

If children spoke their language or practiced their culture, they were punished by methods, including solitary confinement, humiliation, flogging, withholding food, whipping, slapping, and cuffing. Older children were forced to punish younger children.

“The consequences of federal Indian boarding school policies… are heartbreaking and undeniable,” said Haaland.

As part of its initiative, the Interior Department will conduct a year-long “Road to Healing” across the US to allow survivors to tell their stories and establish a permanent oral history collection.

The department says it will produce a second report with the locations of marked or unmarked burial sites, and the names, ages and tribal affiliations of the children buried there.

“It is my priority to not only give voice to the survivors and descendants of federal Indian boarding school policies but also to address the lasting legacies of these policies so Indigenous Peoples can continue to grow and heal,” added Haaland./aa