Calgary, AB,

Calgary fire crews evacuate close to 100 people due to dangerous carbon monoxide levels

At approximately 11:45 pm Tuesday evening, Calgary fire crews responded to a four story residential building located at the 900 block of 18th Avenue SW for an odor complaint called in to 911 by one of the residents. Upon investigation, high levels of carbon monoxide (CO) were discovered on the second floor. Firefighters immediately evacuated the entire building, close to 100 people, and began searching for the source of the CO and odour. Calgary transit busses were brought in to shelter the evacuated residents.

Firefighters used special monitors and found the highest concentration of CO to be 175 parts per million. With the assistance from Atco Gas, it was determined that the probable source of the carbon monoxide was exhaust from diesel trucks which were idling in close proximity to a fresh air intakes and caused dangerous levels of carbon  monoxide to enter the building.

Firefighters ventilated the entire building and monitored each floor for CO levels. Readings of zero were subsequently found throughout the building. Alberta Health Services was on scene and found that there were no reports of any symptoms or injuries as a result of this incident. 

Hazardous material specialists placed carbon monoxide alarms in the building as an added safety precaution for monitoring purposes and residents are encouraged to call 911 back should any of the alarms activate.

CO is an odourless, colourless, tasteless and nonirritating gas which can be lethal after prolonged exposure. In this case, the smell reported to 911 from the initial caller was from the diesel exhaust which contained the dangerous CO.

All residents were allowed back in to the building at approximately 02:00 once it was deem safe by Calgary fire crews.