A storage building went up in flames in Waianae early Saturday.

Six companies with 16 firefighters responded to the alarm at 1:43 a.m. at 86-412 Puhawai Road, according to Honolulu Fire Department spokesman Kevin Mokulehua.

The metal roof of the structure, 30 feet by 30 feet, collapsed onto the contents, making it difficult to get to the heart of the blaze, Mokulehua said.

The fire was reported extinguished at 4:07 a.m. At 8:37 a.m., the fire rekindled. Three fire companies with nine personnel responded, first arriving on scene at 8:45 a.m. No injuries were reported and damage was estimated at $15,000.

Crews used tools to pull apart the smoldering pile of material and applied foam to extinguish the fire.

It was unclear what was being stored.