An arrest was made Tuesday afternoon related to a fire Mar. 24 fire at Philadelphia High School.
A 15-year-old is charged with arson and trespassing. Investigators say he was not a student at the school, and at this time, a motive remains unknown.
Police say the fire is thought to have been set around 6:00 a.m. Friday in a storage room on the second floor of the building. Two classrooms were destroyed and more than a half dozen others were damaged.
Teachers reported back to school Tuesday. Students are to report back Wednesday.