The concrete saw was being used in a nearby suite that was under construction without a state building permit, and smoke detectors near the saw were covered up, authorities said.

While a cause has been determined behind what caused a carbon monoxide leak at a New England day care on Wednesday, it continues to be under investigation.

Exposure to carbon monoxide gas can starve the body of oxygen causing headaches, dizziness and confusion among other symptoms. In the UK , around 30 people die from carbon monoxide poisoning each year, and about 4,000 people are treated in A&E departments.

Seven children were rushed to the hospital after a carbon monoxide emergency inside a Kittery, Maine day care.

There were 27 children and about 10 staff members in the building when there was a possible carbon monoxide leak.

The fire marshal’s office said it operated the building’s heating system in coordination with Maine Fuel Board inspectors and found no concerns related to the emission of carbon monoxide.

Investigators say they have determined the source of the carbon monoxide leak at a Kittery day care center that resulted in multiple children and adults being rushed to the hospital. The Maine Fire Marshal's Office is investigating a carbon monoxide incident that happened at Building Blocks Learning Center off Route 236 in Kittery on Wednesday.

The town said there were 27 children and approximately 10 staff in the day care building. It is unclear if children were hospitalized.

Twenty-seven children and approximately 10 employees were evacuated from the Building Blocks daycare center in Kittery due to CO scare.

State inspection records reveal new details about the York County childcare facility at the center of a suspected carbon monoxide leak Wednesday night.