Calgary condo evacuated after blocked air intake triggers deadly CO buildup

A Calgary condominium complex had to be evacuated when an ice-blocked fresh air intake caused a buildup of deadly carbon monoxide gas.

Fire officials say CO alarms sounded in the four-storey development in the city's northwest around 7 a.m. Wednesday.

The building was evacuated after emergency crews detected levels of between 150 and 200 parts per million of the colourless and odourless gas, but no one was hurt.

Crews cleared the ice from the intake and ventilated the building before allowing residents back in.

Officials say one resident with her own CO alarm in her unit called 911 and went outside when it activated.

The building's own CO warning system then went off, prompting the alarm company to call 911.

Three people in Edmonton escaped from their home Tuesday when a carbon monoxide alarm was triggered. The three were assessed at hospital and released, but the family's pet dog died.

Investigators believe a crack in a heater in the attached garage caused the gas leak.

A statement from Edmonton Fire Rescue Services says crews responded to 557 carbon monoxide calls last year. Since January of this year, they have answered 475 CO-related calls.

Carbon monoxide is created when fuels, such as gasoline or wood, burn incompletely.

The gas initially triggers a headache, dizziness and fatigue and since there can be many other causes for these symptoms, including the flu, CO poisoning is often difficult to diagnose.

Officials say a CO alarm should be placed on every level of a home. They advise to test them monthly, change the batteries annually and replace alarms when they expire.

Nov. 1-7 is carbon monoxide awareness week.