The world is mourning the loss of legendary actor Gene Hackman, who was found deceased in his Santa Fe home this past Wednesday. Alongside him were his wife, Betsy Arakawa, and their dog—both also tragically passed away.

At 95, Hackman had lived a long and remarkable life, yet the sudden passing of his wife, Betsy, who was only 63, has left many questioning the circumstances surrounding their deaths.

In an interview with TMZ, Hackman’s daughter, Elizabeth Jean Hackman, expressed uncertainty about what may have led to the tragedy but suggested that carbon monoxide poisoning could be a possible cause. “The house is fairly modern, built in 2000,” she noted. “But we don’t know if there were any issues with gas leaks or if there were any recent service calls to the property.”