MONROE — Firefighters were on scene less than an hour Halloween morning to check out a natural gas leak outside Northside Elementary School.

"There was no gas inside the school. It was outside the school so that's where the smell was," said Monroe Fire Chief Dan Smits.

The leak appeared to be coming from a malfunctioning boiler inside the school that was vented to the outside, Smits said. There is one remaining, functional boiler to heat the school.

No injuries or harm from the gas were reported.

Firefighters were called to the school shortly before 8 a.m. Thursday. Smits said We Energies also responded.

The malfunctioning boiler was shut down and awaiting repairs, according to District Administrator Rick Waski.

"The leak was a result of a regulator in one of our boilers not working properly and as a result gas was being pushed out of the external exhaust stack," he wrote in an email.

As of about 8:45 a.m., staff at Northside said school would be continuing as normal.

Principal Amy Timmerman sent a message to families of Northside students at about 8:30 a.m. to announce that the fire department "has checked the entire building and everything was in the normal range."

"At this time, we will be staying in the building until we have clearance that going outside is safe as well," she wrote.

About an hour later she sent another message to inform families that "it has been deemed safe for students to go outside for recess today."