Twelve Camp Avenue School students were transported to the hospital after a minor oil puff back on Thursday.
There were no serious injuries.
According to David Feller, superintendent of North Merrick Schools, a maintenance man was doing routine work on a boiler located on the lower level of the school when he noticed a plume come out of it and then shut the boiler down.
"There was a class of sixth graders not too far from where the boiler was," Feller said. "When the children started feeling sick, we brought it to the nurse's attention and decided to call 911."
James Rogers, 1st Assistant Chief of the North Merrick Fire Department, said that the smell of gas caused students to get headaches and feel nauseous, but they were not seriously harmed.
"They are doing well and they are all alert," he said.
The school was evacuated, but children were able to go back in a short time later.
"Once the fire department declared that it was OK and there were no levels of carbon monoxide found, the children were let back in," Feller said. " We will have regular dismissal today."