Saskatoon Fire says four people were treated for carbon monoxide poisoning last night at an underground parking lot under construction in the Evergreen neighbourhood on Horner Crescent.
According to the fire department, crews located one patient who was suffering effects from carbon monoxide.
Crews then put on proper protective gear to tour the parking lot and found three more patients inside the garage also suffering from carbon monoxide poisoning.
Those suffering from carbon monoxide poisoning were all pulled out of the garage safely and moved to waiting ambulances for hospital transport. It is unknown if the patients were taken to the hospital or what their current status is.
According to the City of Saskatoon, the initial cause of the high levels of carbon monoxide is thought to be from a concrete power trowel. It was being used inside of the building.
Fire crews searched the rest of the building, but they did not find anyone else.
Fans were set up inside the garage to help ventilate it.
The scene has been turned over to Saskatchewan Occupational Health and Safety.