A 911 call came in just after 6:30 a.m. Friday about a 76-year-old man who was semi-conscious on the first floor of a cottage house on a property in Solebury Township, Bucks County.
Medics removed the man from the building and rushed him to the hospital.
Chopper 6 over fatal carbon monoxide incident in Bucks Co.
Rescuers then learned of a 76-year-old woman who was also in the home. They found her unconscious in a second-floor bedroom and tried to revive her, but she was pronounced dead at the scene.
Family members in the main house on the property were not affected.
The Bucks County Coroner identified the 76-year-old as Dayle Haddon, who gained international fame in the 70s, gracing the covers of fashion magazines.
In August, she was featured in Vogue. She also starred in movies, and in recent years became an activist for numerous causes.
"She was chic, elegant. She always remembered you," Sandy Linter, a renowned makeup artist and longtime friend of Haddon, said in an exclusive interview with Action News. "It was a tragic accident. I'm sorry. I'm so sorry for her family."
Firefighters on the scene detected a high level of carbon monoxide in the property. Police say fumes from a boiler may be to blame.
"It is believed a heating unit, a boiler unit, is the source of the carbon monoxide. The initial readings on EMS and fire company arrival were extremely high, so we're treating this as a carbon monoxide poisoning incident," said Det. Sgt. Jonathan Koretzky of the Solebury Twp. Police Department.
Two medics were taken to Doylestown Hospital for carbon monoxide exposure, and a Solebury Twp. police officer was treated at the scene.
WATCH: Renowned makeup artist Sandy Linter speaks about death of Dayle Haddon | EXCLUSIVE
Renowned makeup artist Sandy Linter speaks about death of Dayle Haddon
The circumstances of this incident remain under investigation.
Real estate records show the home belongs to actor Marc Blucas and his wife, journalist and producer Ryan Haddon Blucas. They bought the property for $1 million in 2012.
Marc Blucas is seen in a Hallmark Channel interview talking about rehabbing the home that dates back to the 1700s. He is known for roles in Buffy the Vampire Slayer and Hallmark movies.
On Friday night, Dayle Haddon's daughter, Ryan, posted a tribute on Instagram saying, "She held so many up, saw their greatness sometimes hidden to them, and always built bridges with her own connections to help them ascend. She was everyone's greatest champion. An inspiration to many."
Firefighters want to remind the public that carbon monoxide is odorless, colorless, and tasteless. It can be dangerous all year round but especially in the colder months. They say prevention and detection are key.
"Prevention is about keeping your heaters, appliances, fireplaces, your hot water heater and your chimneys in good working order. Detection is about having a working, at least one working, carbon monoxide detector in the house," said Deputy Chief Mark Nissenfeld with the New Hope Eagle Fire Company.