UPPER ARLINGTON, OH (WCMH) — Students and staff at Upper Arlington High School were sent home early Wednesday because of a mysterious, noxious odor inside the building.

School Principal Andrew Theado says custodians reported the gasoline-like smell about 8:15 am. Students were in the first period classes at the time.

Theado says the building was evacuated while members of the Upper Arlington Fire Department searched, unsuccessfully, for the source. “It was bizarre because you’d think it would go away unless there was something there causing the smell,” Theado said.

Nobody was sick or overcome by the fumes but after a couple of hours, the decision was made to cancel classes for the rest of the day.

Investigators and school staff checked crawl spaces, lockers, trash cans, carpets, ceiling tiles as the smell lingered for hours.

Finally, by late afternoon, the smell was gone but the mystery remains.

“We had an environmental crew come in this afternoon and they determined there was nothing in the air that was cause for alarm,” Theado said. “The smell has gone and the fire department couldn’t find where the smell was coming from either but we do know it’s gone.”

All evening activities at the school were cancelled. But Theado expects things will be back to normal on Thursday. “We feel the building is safe,” Theado said. “We’ve been told the building is safe to occupy tomorrow. We’re going to have people here overnight – our third shift custodians – checking out things and if something changes we’ll get a communication out.”