A 63-year-old woman has died from injuries suffered in a carbon monoxide leak in Southeast Portland last month that also killed her husband, authorities said.

Brian and Yoko Perry’s eldest son found the pair unconscious on Dec. 9 in their home in the 1600 block of Southeast 12th Avenue, said Lt. Allen Oswalt, a Portland Fire spokesman.

Brian Perry, 64, was not breathing. He was pronounced dead soon after emergency crews responded to the home.

Yoko Perry was barely breathing. She was rushed to Providence Medical Center in Northeast Portland, where she was placed in a hyperbaric chamber designed to dislodge carbon monoxide from a patient’s blood.

She was officially pronounced dead on Dec. 22, the Multnomah County Medical Examiner’s Office reported. Her official cause of death was asphyxia by carbon monoxide causing terminal cerebral anoxia.

A heater improperly installed in a room without proper ventilation was responsible for the carbon monoxide leak, Oswalt said.