Fleetwood Area Middle School is closed Friday after multiple people were sickened in what the superintendent calls a carbon monoxide problem Thursday night.
Emergency crews were called to the school around 8:30 p.m. for reports of several people suddenly feeling ill.
The superintendent, Greg Miller, said the Fleetwood Community Theater group was holding a dress rehearsal for a performance that's supposed to be Friday night, when suddenly, a few of the people on stage became ill.
Some experienced light-headedness, while others were feeling nauseous.
"One at a time, we had a few of them become ill, not feel well, light headedness," Miller described. "Because of it escalating from one to the next, the director who was there did call 911 because of the quick escalation."
The building was evacuated, and Miller said two adults and six children needed medical attention.
"I originally started feeling dizzy and sick, and then I kind of just don't remember much," said actor Paige Rothermel.
Rothermel is one of the eight people taken to the hospital to be treated for exposure to carbon monoxide.
"I was just out of it," she said. "I really don't remember much."
Rothermel's sister said the sickness seemed to hit at once.
"It was actually kind of horrifying to see all of my friends go down," said Mackenzie Heffner.
Other activities were taking place in the building at the time, but the incident appears to have been isolated to the auditorium area.
Miller said authorities believe carbon monoxide caused the sicknesses, but fire officials could not find any traces of carbon monoxide in the building.
The middle school was closed Friday as a precautionary measure.
"We brought in a mechanical contractor today to just go through all of the combustible components -- our boiler, our hot water heaters," Miller told 69 News. "They are going through and they're re-certifying all of that equipment to ensure that that's not giving off any kind of carbon monoxide."
All other buildings in the district operated on a regular schedule.
Everyone impacted in doing OK.
"I'm very happy we all made it through this," Rothermel said.