A woman and her son were found dead Tuesday morning in their home in Shinagawa Ward, Tokyo, and her daughter was unconscious, police said.

They are treating the case as a suicide pact.

A police officer entered the house at 10:20 a.m. and found Tomoko Eguchi, 63, her son, Makoto, 34, and daughter, Junko, 37, unconscious.

Eguchi and her son were later declared dead from carbon monoxide poisoning linked to burning charcoal. Eguchi's 63-year-old husband suffered minor cuts to his left wrist, police said without elaborating or providing his name.

Police were questioning the husband and said they learned he contacted an acquaintance to say he and his family planned to commit suicide due to heavy debts.