Dozens of residents living in an apartment building in the community of Sunnyside were forced to leave their homes on Wednesday over concerns of a potential carbon monoxide leak.
Firefighters were called to the building in the 1000 block of 2 Avenue N.W. at around 9:30 p.m.
The Calgary Fire Department (CFD) said crews found elevated CO levels, which they believe were caused by a faulty mechanical unit.
The issue was fixed and firefighters ventilated the building before allowing the 30 to 40 back inside.