Eleven third- and fourth-grade students were taken to the hospital on Thursday as a precautionary measure after reporting “respiratory distress,” despite the fact that investigators could not determine a possible cause of illness.

More than 100 students at Wentworth School in Scarborough, Maine, were assembled on risers on the school’s cafeteria stage practicing for an upcoming concert when one student passed out and others began to “make physical complaints of a respiratory nature,” the school’s superintendent said during a press briefing.

Emergency medical services were called to the scene just after 10 a.m., and the 11 students were taken to hospital “for further evaluation and precautionary measures,” Scarborough schools’ Superintendent Dr. Diane Nadeau said.

The remaining students were walked to nearby Scarborough High School, while fire investigators worked to determine a possible cause of the reported illnesses.

Scarborough Fire Chief Rich Kindelan said they received a report of a potential gas leak “and some students in respiratory distress.” (WGME)

“We did meter the building twice from two different fire department meters as a redundancy, just to make sure,” Kindelan said. “And there were no hazards found in the building or in the area of the incident.”

“The school does have fire detection and carbon monoxide detection in the areas that it’s required,” he continued. 

A Google Maps look at the school in Scarborough, Maine. (Google Maps)

The school’s superintendent said the temperature was not assessed at the time the students were grouped together on the risers. She was unclear if the school concert would go on Thursday evening. 

Fox News’ Jennifer Johnson contributed to this report.