Officials say 19 students and employees at a Utah high school were treated for respiratory distress after a student released pepper spray.
Park City fire information officer Tricia Hazelrigg says police were called to Park City High School about 2 p.m. on Monday.
Hazelrigg says law enforcement officials confirmed the substance wasn't natural gas but an "unknown substance."
Park City Police Capt. Phil Kirk says the student later called the school and admitted to releasing pepper spray. He did not immediately know how it had gotten into the school's air system.
Hazelrigg says some who were affected experienced burning in their lungs and abdominal cramping.
Hazelrigg says one person was taken to a hospital.
Hazelrigg says the school was not in session when the incident occurred.