MONTGOMERY — The Montgomery Area School District is closed until Monday following a fire that broke out late Thursday morning in the high school’s dust collector, which is used for the school’s woodshop.

Although the fire was small and extinguished in a short period of time, the school’s air conditioning and heating ventilation system pulled much of the outside smoke from the fire back into the large complex, Clinton Township Fire Chief Todd Winder said.

The large building at 120 Penn St. houses the high school, middle school and elementary school as well as the district’s administrative offices.

Firefighters were dispatched to the scene about 11:20 a.m. after a teacher pulled an alarm upon discovering the fire, Winder said.

“In some areas of the building there was a very light haze while in other parts there was very thick smoke,” Winder explained.

The fire has been ruled accidental and was caused by a spark from a computer-generated machine, he said, adding the spark was enough to ignite dust in the dust collector.

Joining Clinton Township firefighters were volunteers from Montgomery, Washington Township, Hughesville, Picture Rocks, Muncy Area and South Williamsport.

Additional resources were used to obtain several additional exhaust fans needed to blow all the smoke back out of the two-story building.

While the ventilation system spread smoke throughout the schools, actual fire damage was confined to the ductwork in the school’s dust-collection system, Winder said.

Two things truly helped contain the emergency situation, Winder said. The dust collector had been cleaned out and serviced earlier this week, “so there was not as much product in the collector to burn,” he said.

Also, when the shop teacher discovered the fire, a few students quickly grabbed portable extinguishers and worked together to prevent the flames from spreading.

Students were already evacuated from the schools when firefighters arrived on the scene.

District staff and other personnel will spend today and the weekend cleaning the building so that classes can resume on Monday.

“All the smoke detector heads have to be cleaned and serviced,” Winder said.

He praised district administrators and the staff in working together with the fire companies. All classes were canceled for the day as of 12:15 p.m.