The Osaka District Court sentenced a couple to 13 years in prison Thursday for confining their eldest daughter, who had schizophrenia, for over 10 years and letting her freeze to death.

Presiding Judge Takushi Noguchi said the parents, who faced charges including the abandonment of their duties as guardians resulting in death, committed an “inhuman act that neglected the minimum dignity of a human being.”

According to the ruling, the parents began to confine their daughter, Airi Kakimoto, around March 2007 in a prefabricated hut on the premises of their house in the city of Neyagawa, Osaka Prefecture, and had her live naked in the building.

Around Dec. 18, 2017, the father, Yasutaka, 57, and the mother, Yukari, 55, let the daughter, then 33, freeze to death, with her death stemming mainly from malnutrition, the ruling said.

In the lay judge trial, the defense for the parents claimed their innocence, saying they kept the daughter in the hut for treatment, not for confinement.

The judge said, however, that the parents “did not give minimum consideration for her health,” as her teeth had fallen out and she was so thin that her ribs were visible.

“It’s utterly impossible to assess that the parents made efforts to treat their daughter,” the judge said.

The parents deprived her of freedom of action and prevented the health of her body and mind from developing by isolating her from society, the judge also said, adding that they were “utterly irresponsible.”

A man in his 40s who served as a lay judge in the trial told a news conference that the case was “heartbreaking, as no salvation for the daughter was found.”

“The parents should have loved their daughter,” he added.