A fire caused about $5,000 in damage to a portable classroom outside Joppatowne High School on Wednesday, the Joppa-Magnolia Volunteer Fire Company reported.
Firefighters responded to the call at about 10:09 a.m. Smoke was reported showing from the one-story classroom.
"A small fire was quickly extinguished inside the walls and ceiling of the classroom," the Joppa-Magnolia company reported in an e-mail. "The source of the fire was found to be a malfunctioning air conditioning unit that was attached to the classroom."
The state Fire Marshal's Office was notified, but did not respond to the scene.
No one was injured.