SANTA FE, N.M. (AP) — Actor Gene Hackman died of heart disease a full week after his wife died from hantavirus in their New Mexico home, likely unaware that she was dead because he was in the advanced stages of Alzheimer’s disease, authorities revealed Friday.

Betsy Arakawa died of hantavirus pulmonary syndrome at the age of 65, New Mexico health authorities said. Here’s what to know about the rare but deadly disease.