A Winnipeg daycare building was evacuated after a carbon monoxide scare Thursday morning.

Emergency crews were called to the Peek-A-Boo daycare in the 3100 block of Portage Avenue around 10 a.m.

A carbon monoxide detector went off and 54 children and19 staff members were removed from the building. Everyone was assessed by medical staff aboard three buses, which took people to the HSC Children's Hospital.

The children ranged in age from a few months to about six years old, said health officials.

HSC staff worked with parents as they arrived to direct them to a staging area where staff reunited them with with their children, said health officials.

Around 4 p.m. Thursday, health officials said all the children and staff had been treated and released.

The daycare had recently installed the carbon monoxide detectors.

"Our furnace company suggested we get them, just to be extra safe, so we got them. We've had them for about a week," said Jan Ranson, executive director with the Peek-A-Boo daycare.

Some parents said the fact the daycare had the detectors was reassuring.

"(It's) very, very important because if they didn't have an alarm, who knows how long (the kids) would have been in there for," said Corrie Balas, whose 16-month-old daughter goes to the daycare.

Daycare officials said the facility has an evacuation plan, which was followed on Thursday.

Fire officials confirmed low amounts of carbon monoxide were found in the air.

"It is critical but with the low level, it's over a period of time and there are usually other symptoms that kick in, such as nausea or headache or vomiting," said Bill Clarke from the Office of the Fire Commissioner.

Manitoba Hydro said they confirmed the carbon monoxide leak was traced to one of the rooftop gas heaters.

Once the leak is fixed and the air is deemed safe, everyone will be allowed back in, said Hydro officials.

- with a report from CTV's Karen Rocznik