Feller said the affected children were in the school’s general-purpose room, not their regular classroom, when they began feeling nauseated. He added that several other children in the class “reported no symptoms whatsoever.” He also said Pascarella went by ambulance to NUMC along with her affected students.

An email notification the school district sent to parents stated that the incident’s cause was “some black smoke [that] puffed out of a boiler.”

Rogers confirmed the same.

“The oil burner had a small puff-back,” Rogers said. “We had a small classroom of children next to the oil burner room that were exposed possibly to the carbon monoxide that was going off.” He said everyone affected by the “puff-back” remained conscious.

“This may have been some kind of routine maintenance that was going on with boiler,” Feller told reporters Thursday outside Camp Avenue School. “That’s something that we are investigating.“

Kevin Osborne, a Camp Avenue parent, said he first learned of what was happening at the school when his and his wife’s phones both received school alerts at 2:18 p.m. He said he was concerned by the information, but not scared.

“We have good people here,” Osborne said, referring to school officials.