LANCASTER, S.C. (QUEEN CITY NEWS) – Several students and their bus driver were exposed to an unknown substance Wednesday afternoon, according to the Lancaster County Sheriff’s Office.

One of the students, a 14-year-old girl, was found unconscious after deputies found the Indian Land High School bus at about 5 p.m. near the bus office behind the school stadium.

More than 40 students were on the bus, and some also showed signs of exposure. Officials removed everybody from the bus and EMS treated the patients at the scene. Parents were notified to pick up their children.

“I want to assure parents that we are treating this matter seriously and will conduct a thorough investigation to determine what caused this exposure,” Sheriff Barry Faile said.