People are spinning this story like this was a death camp for native kids. It's not. It was a real tragedy that children were removed from their parents forcibly and the institutions couldn't be bothered to report if your kid freaking died...
Given the period in time and lack off oversight, I don't doubt there was abuse too, and let's not forget this is the Catholic church, which has a poor record, but it's clueless to account these deaths to abuse just on the basis of possible graves existing on ground penetrating radar. We're not even sure these are all graves, you have to excavate to have an idea what the error rate is.
One last thing to keep in mind is at this point in time the government barely existed. There were no social safety nets or programs and hardly any government oversight out west. It's called the wild west for a reason. The church was operating these schools as a charity because the government had neither the resources not inclination to do it themselves.
Things were different back then, and they often don't look good judged through our modern eyes. That's a sign of how far we've come in less than a century.
To us today this looks about the same as what the Chinese are doing to the Uighurs. Definitely not a moment in history to be proud of.
[1] https://www.statista.com/statistics/1041751/canada-all-time-...