Louise Dean School was evacuated Friday afternoon after a caretaker smelled gas.
At about 1:30 p.m., the Calgary Fire Department, paramedics and police were sent to the Louise Dean School on 23rd Street for reports of a strong smell of gas.
The school's caretaker reported the gas odor in the building's boiler room.
Firefighters immediately evacuated the school. About 100 students and staff were sent to an adjacent church.
Firefighters ventilated the school and believe they found the source of the carbon monoxide in the boiler room.
At the time that the carbon monoxide values reach safe working levels, staff will enter the building to pinpoint the problem.
It is unknown at this time if the air quality of the school will be returned to normal levels in time for school to resume this afternoon.
Paramedics tended to one adult on scene for minor concerns.