A Tennessee high school reportedly evacuated students Thursday after a district-contracted custodian intentionally left a gas valve running in a classroom overnight.

Hardin Valley Academy (HVA), a high school within Knox County Schools (KCS), notified families it was evacuating due to a "gas odor" within the building. HVA leadership said it was a precautionary action.

KCS has yet to publicly provide further information, however, the Knox County Sheriff's Office (KCSO) reportedly concluded that an employee was behind the incident. 

A "contract custodian" was arrested and later terminated Thursday for "intentionally" leaving a gas valve running in a HVA science lab, according to WATE 6 News. 

A spokesperson for KCS told WATE 6 News that no gas was detected in the air Thursday, and the evacuation was to avoid both the "lingering odor" and "disruption to the learning environment." 

Classes reportedly continued as normal throughout most of the morning, with fans kept running and doors open to ventilate the school.

In a social media post Friday, HVA told families that it understands their concerns, and it is "working to process the event and to ensure a safe learning environment."

A HVA student-led protest was canceled Friday to maintain a "normal" learning environment. It is not immediately clear what the subject of the intended protest was.

KCS reportedly hired 50 contracted custodians in January to maintain 17 of its schools for the remainder of the academic year, including HVA. School board members expressed hesitancy over the decision, with some saying the move wouldn't solve the true issue of poor working conditions and low pay for custodians.

Crisis in the Classroom (CITC) has reached out to both KCS and KCSO for comment and additional information surrounding Thursday's evacuation, but did not receive a response prior to publication. This story will be updated if a response is received.