Schererville, IN- – A faulty heater for an indoor swimming pool filled a home with carbon monoxide and fumes, killing a woman and sickening her husband, authorities said Saturday.

Sheila Sikora, 56, was pronounced dead at the scene Friday after her mother, who grew worried when she couldn’t reach Sikora on the telephone, found her unresponsive in her home.

Sikora’s husband, Vernon, was taken to a Hammond hospital and placed in a hyperbaric oxygen chamber to reduce the carbon monoxide levels in his blood. He was released later Friday.

Carbon monoxide levels in the home were so high the readings were off the scale of the department’s multigas monitor, said Mark Senethy, assistant chief of operations for the Schererville Fire Department.