The blaze was declared under control less than a half hour after the call came in at 12:10 p.m.
"Those radiators are 45, 50 years old or more," Mayor Thomas Calabrese told Daily Voice.
Calabrese commended everyone involved -- from police and firefighters to Office of Emergency Management personnel to school administrators and teachers -- for their professionalism in handling the situation.
School personnel "tried to put it out with an extinguisher, then firefighters had to drop in a line," one responder told Daily Voice. "Smoke went up to the second floor."
Students and staff who were taken to School No. 6 were returned just before 1:30 p.m.
"We brought them back to the school cafeteria so they could collect their things," Police Chief Richard Gaito told Daily Voice. "Then all of the students were sent home."
A police official from a nearby town who spoke on condition of anonymity said all precautions must be taken in such instances.
"There have been active shooter situations where they tried to lure people in or out," he said. "First responders are always ready for anything."
Police and firefighters from neighboring towns assisted.
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