Students and staff at Cornwall Central High School were evacuated Thursday due to the scent of gas, according to an email sent out to parents.
Officials said in the email that everyone was safe and waiting for the next instructions from outside the school.
Students and staff won't be able to go back inside the building until it's fully aired out.
Students were dismissed for the day.
Once the fire department deems it safe for re-entry, students will be sent a message via Parent Square so that they can collect their belongings later Thursday, according to the superintendent.
The superintendent says students can also keep their belongings at the school until Friday. They anticipate that school will be open on Friday.