Firefighters extinguished the second fire this week at Kahuku High School on Friday night.

At about 9:35 p.m., firefighters responded to the school at 95-490 Kamehameha Highway and found a small amount of smoke and flames coming from the roof and inside of a classroom, said Honolulu Fire Capt. David Jenkins.

Firefighters extinguished the fire by 10:14 p.m. and were investigating the cause, Jenkins said. A damage estimate was not available.

Jenkins said the building was closed and unoccupied at the time.

At about 2:50 a.m. Tuesday, a fire started inside a bathroom ventilation duct at the school. Responding firefighters found light smoke and flames coming from the roof of the administration building and extinguished the fire by 3:34 a.m., Jenkins said.

The cause of that fire was undetermined. Damage was estimated at $2,000.