Fargo firefighters responded to a report of a gas smell Wednesday morning at 4820 30th Ave. S.
The office building is two stories and contains businesses and a daycare. When firefighters arrived, they found elevated carbon monoxide readings throughout the building but no indication of any type of flammable gas.
Firefighters say CO readings varied in the building from 25 parts per million in the daycare to 70 ppm on the second floor. The office spaces were evacuated and the children in the daycare were moved to a room with low CO readings. About 15 adults and 20 children were evaluated from the building.
The cause of the elevated CO was a construction crew using a gas-powered concrete saw inside the building without ventilation.