Canadian-born actress and supermodel Dayle Haddon has died after a suspected carbon monoxide leak at the Pennsylvania home of her son-in-law, Hallmark movie star Marc Blucas. Solebury Township Police arrived at the residence in Bucks County on Friday just after 6:30 a.m., according to a police report. They were called to the home on Phillips Mill Road in New Hope to investigate reports of a man passed out on the property, which is owned by Blucas and Haddon’s daughter, former journalist Ryan Haddon, CBS reported. When they arrived on the scene, first responders found an unconscious 76-year-old man on the first floor of a detached “in-law” suite, police said. He was rushed to Robert Wood Johnson University Hospital in New Jersey, where he’s currently listed in critical condition. He was identified on Saturday as Blucas’ father, Walter J. Blucas, of Erie, Pa. First responders also found an unresponsive woman in a second-floor bedroom of the in-law suite, police said. They attempted to revive her, but to no avail, and she was pronounced dead at the scene, ABC 6 reported. The Bucks County Coroner’s Office has since confirmed the victim to be 76-year-old Haddon. Her cause of death has not yet been determined, but an autopsy report will be completed to confirm what killed the former starlet. According to police, volunteer firefighters detected a “high level of carbon monoxide” on the property. Two medics were transferred to the hospital for carbon monoxide exposure, while a police officer was also treated on the scene. Family members in the main house were not affected. While an investigation into the matter is ongoing, police believe “a faulty flue and exhaust pipe on a gas heating system caused the carbon monoxide leak.” Born and raised in Toronto, Haddon dipped her toe into performing in her teens, first as a ballet dancer, according to her IMDb page. She began modeling shortly thereafter and moved to Hollywood in her 20s, where she quickly landed a role in the 1973 Disney movie “The World’s Greatest Athlete.” As a model in the 1970s and ’80s, Haddon appeared on the covers of Vogue, Elle, Cosmopolitan and Esquire, as well as the 1973 Sports Illustrated Swimsuit Issue. Haddon left modeling after giving birth to her daughter, but returned to the workforce following her husband’s death in the mid-1980s. She went on to break barriers for models in their late 30s and 40s, signing major contracts with cosmetics companies including Clairol, Estée Lauder and L’Oréal. She penned two books on ageless living and hosted beauty segments for ”The Early Show” on CBS. “I kept modeling, but in a different way,” she told The New York Times in 2003. “I became a spokesperson for my age.” View this post on Instagram A post shared by @women1one In her later years, Haddon became an ambassador for UNICEF and founded WomenOne, a New York-based organization dedicated to creating educational opportunities for women and girls around the world. Her son-in-law, Marc Blucas, attended Wake Forest University on a full basketball scholarship before making the switch to acting. He caught his break in the 1996 flick “Eddie,” landing a role that required his athletic abilities. Blucas also starred opposite Katie Holmes in “First Daughter” and later appeared in “Buffy the Vampire Slayer” as Riley, one of Buffy’s love interests. He’s also well-known for his roles in several Hallmark holiday films, including “Miss Christmas,” “Season for Love,” “The Irresistible Blueberry Farm,” and “Operation Christmas.”