Honolulu firefighters extinguished a second fire in three days at Kahuku High School.
HFD officials say the flames broke out in a classroom just after 9:30 p.m. Friday.
Some 19 personnel responded and had the flames fully extinguished by 10:14 p.m.
The cause of the fire is under investigation.
Earlier in the week, on May 9, a fire broke out at the school's administration building.
Nearly 20 firefighters responded around 2:50 a.m. Tuesday morning, and found smoke and flames coming from the rooftop.
The fire was under control by 3 a.m. and fully extinguished by 3:35 a.m.
No one was inside at the time.
HFD says they were unable to determine a cause, but say the fire originated from the vent of a bathroom inside the building.
Damage is estimated at $2,000.
Copyright 2017 Hawaii News Now. All rights reserved.
SLIDESHOW: Black Friday 2017 Deals
PHOTOS: Child's wish comes true at Foster Botanical Garden
PHOTOS: Zoo's new 'reptile house' opens
PHOTOS: Sand sculptures in Waikiki
PHOTOS: Hawaiian Air welcome first Airbus A321neo