A southwest Ohio teacher says she and her husband owe their lives to police and co-workers who became concerned when she didn’t show up for work.

Colleagues of teacher Donna Elsen at Lakota Ridge Junior School in suburban Cincinnati noticed Monday when the usually punctual Elsen was late. Concern grew when calls to Elsen’s home went unanswered and her husband, Jack, did not show up at his workplace.

Police were alerted and found Jack Elsen slumped in a chair and Donna Elsen unmoving on the floor.

Both had been overcome by carbon monoxide gas from their heating system. They were treated at a hospital and returned to work a few days later. The Elsen’s dog and cat did not survive.