Authorities are investigating two separate fires at Valley High School Tuesday.
The first fire started before noon in a bathroom. No one was injured but the school suffered minor fire damage and significant water damage.
A 16-year-old student faces arson charges in that case.
Two hours later, officials were called to a second fire in another bathroom.
No one was injured but the school suffered additional damage.
Police are trying to figure out if the two fires are related.