The death of a 33-year-old Sri Lankan migrant, trapped in the bowels of Japan’s immigration system, triggered national calls to reform the bureaucracy that allowed her to waste away in a detention center without proper medical treatment.

A government report Tuesday detailed the missteps that contributed to the tragedy, including insufficient medical resources, communication failures and a lack of proper oversight. But activists and politicians said the proposed changes did not go far enough to address the fundamental failures in an immigration system they describe as opaque and capricious.

The nearly 280-page document describes the series of events that led to the death in March of Ratnayake Liyanage Wishma Sandamali, who had been detained for overstaying her visa. While the report said her death was the "result of illness,” it noted the possibility that her health was affected by several factors, "making it difficult to concretely determine the cause.”