Students and staff at Sacred Heart School in Port Lambton evacuated the building Thursday because of a gas leak.
St. Clair Township Fire responded to the call at about 11:15 a.m.
Chief Richard Boyes said when stations from Port Lambton and Wilkesport arrived on scene, the building was already being evacuated.
"The contractor had notified the school that they had cut a gas line," said Boyes. "Then we proceeded to do vapour suppression and make sure the evacuation was complete. The first concern is obviously where the vapour cloud is going and are any of the people in the area in danger?"
Boyes said the students were first taken to the back of the school before being moved to the nearby cemetery. Parents were then called to pick up their children.
"The school did a great job of evacuating the students, that's what they train for."
Enbridge Gas also responded to turn off the natural gas supply to the damaged line.
The school is undergoing a $4.2 million renovation project, which includes the removal of portables, new classrooms and child care rooms.
Boyes said it's a reminder to call before you dig.
