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

The concrete saw was being used in a nearby suite that was under construction, and smoke detectors near the saw were covered up, authorities said.

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.