Dayle Haddon, the actress and model, has died from suspected carbon monoxide poisoning at the Pennsylvania home of her son-in-law, actor Marc Blucas. Authorities are investigating the incident, which also resulted in the hospitalization of a 76-year-old man and exposure of first responders to the gas.

Solebury Township Police responded to a 911 call at a residence on Phillips Mill Road early Friday morning. Upon arrival, they discovered a 76-year-old male unconscious on the first floor of a detached in-law suite. The individual was promptly transported to a hospital for treatment.

Tragically, officers also located Haddon, 76, deceased in a second-floor bedroom within the home. Preliminary investigations by the Bucks County Coroner's Office revealed elevated levels of carbon monoxide at the residence. The official cause and manner of Haddon's death is still pending further investigation.

The situation remains under active investigation. Beyond the primary victims, two medical personnel and one police officer who responded to the scene were also treated for carbon monoxide exposure. The incident has been described by authorities as a “tragedy.”

Haddon's career encompassed acting roles in films such as “The World’s Greatest Athlete” and “North Dallas Forty.” Moreover, she distinguished herself as a model, notably being the only individual to have contracts with four prominent cosmetic brands: Revlon, Max Factor, Estée Lauder and L’Oréal.

Beyond her professional achievements, Haddon served as a spokesperson for L’Oréal for over 15 years, acted as a UNICEF ambassador, and founded the charitable organization WomenOne, which concentrates on the education of women and girls.

Ryan Haddon, Dayle’s daughter, described her mother as an “inspiration” in a social media post. She remembered her mother’s “power,” kindness, and creativity and acknowledged the unique and unknowable nature of death.

Representatives for both Haddon and Blucas have not yet issued a public statement. This story originally appeared on NBCNews.com.