Dayle Haddon, a Canadian model and an actress who appeared in numerous films, died at age 76.

She was found dead from suspected carbon monoxide poisoning at the home of her daughter, Ryan Haddon, and son-in-law, Buffy the Vampire Slayer actor Marc Blucas. Born in Montreal in 1948, Dayle Haddon trained as a dancer and joined the Les Grands Ballets Canadiens at age 13 before being crowned Miss Montreal at 18.

She had a highly successful modeling career in the 1970s and ’80s, landing on the cover of Sports Illustrated’s 1973 Swimsuit Issue as well as in issues of Vogue and Elle.

She most recently appeared alongside Blake Lively in Baz Luhrmann’s To Catch a Thief–inspired shoot for Vogue’s September issue. Haddon represented brands like L’Oréal, Estée Lauder, Max Factor, and Revlon, finding particular success promoting anti-aging products for women over 35.

She also appeared in supporting roles in several films, including The World’s Greatest Athlete, Madame Claude, North Dallas Forty, Cyborg, Bullets Over Broadway, and Celebrity.