In recent weeks archival documents have revealed nutritional, dental and medical experiments that took place at the school.
Now historical reports, just released by the federal government, show a disturbing rate of tuberculosis among the students.
A survey from 1946 shows that 100 of the 132 children at the Cecilia Jeffery School suffered from the potentially fatal disease.
"These kids were known to be sick with this particular illness, and still being exposed to the other First Nations children who were sleeping in the dorms," said Larry Henry, a support worker for residential school survivors with Grand Council Treaty 3 in Kenora.
Henry attended Cecilia Jeffrey Indian Residential School as a small child in the 1960s, before being sent on to another residential school in Fort Frances, Ont.
Later, as a teenager, he was diagnosed with tuberculosis, which he said he likely contracted in residential school.
"I remember the X-rays [being taken at the school] that came back," Henry said.
"But who looked at them? Did the supervisor or the nurse -- and was she an expert in whether or not to quarantine a group of children? I'm not sure," he said.
The documents show that a few students were sent to a sanitarium. But, Henry said, that has raised other problems for survivors.
The time students spent in the sanitarium is not counted towards a compensation claim through the Indian Residential School Settlement.
"I think it's only fair that these students have that opportunity to be recognized [with compensation], because they were away from home, and the responsibility of the school and then sent away to an institution to be treated, and then taken back to their residential school," Henry said.