Calgary Fire Responds to Dangerous Carbon Monoxide Incident in Marlborough Home

Fire crews responded to a dangerous carbon monoxide incident in northeast Calgary on Friday morning after emergency responders detected high levels of the gas inside a residential property.

At approximately 8:25 a.m., crews were dispatched to the 4700 block of Marbury Place NE in the Marlborough neighbourhood following a carbon monoxide (CO) alarm activation. An Emergency Health Services (EHS) ambulance crew was already on scene for a medical call when their CO monitor was triggered.

The ambulance crew immediately evacuated themselves and one adult patient from the front entrance area and requested assistance from the Calgary Fire Department.

Upon arrival, fire crews detected carbon monoxide levels of 500 parts per million (ppm) inside the home — a concentration that can be fatal within hours of exposure. For comparison, firefighters typically evacuate structures when CO levels reach 50 ppm.

Wearing self-contained breathing apparatus (SCBA), crews safely entered the home and located a second patient, who was also removed from the residence. EHS personnel assessed both patients and transported them to hospital for further care.

Firefighters conducted a full search of the property to ensure no additional occupants or animals were inside. The furnace was shut off, and crews ventilated the home using electric fans until carbon monoxide readings returned to zero. ATCO Gas attended the scene to assist.

The Calgary Fire Department is reminding residents that working carbon monoxide alarms are critical and should be installed on every level of the home, especially near sleeping areas.

Officials noted that while hot air and gases like carbon monoxide typically rise, extreme cold weather can create a thermal inversion. During these conditions, cold air acts like a lid, trapping gases inside a home and allowing CO levels to build up more quickly.

The most common source of carbon monoxide in homes is the furnace. However, any fuel-burning appliance — including those powered by natural gas or propane, as well as fireplaces — can produce CO. Regular maintenance and inspections by qualified professionals are recommended to ensure appliances are operating safely.

Vehicles are another common source of carbon monoxide exposure during winter months. Authorities warn residents never to idle vehicles inside enclosed spaces such as garages or near building air intakes.

Symptoms of carbon monoxide exposure can resemble the flu and may include headaches, nausea, dizziness, confusion, fatigue and loss of consciousness.

A carbon monoxide alarm that emits a continuous four-beep pattern indicates the presence of CO. In such cases, residents should immediately leave the building and call 911. When contacting emergency services, callers should inform dispatchers if anyone is experiencing symptoms.

Carbon monoxide alarms should be installed on every level of the home, including basements, and especially near bedrooms to ensure they can be heard during sleep. Alarms are widely available at hardware stores. Officials advise residents to ensure any CO alarms purchased, particularly online, meet Canadian safety standards.