A fire early Wednesday which caused over $100,000 damage to a 104-year-old wooden structure that houses Central Union Preschool & Kindergarten was deliberately set, according to police who are investigating the incident as a first-degree arson.

Capt. Robert Main said tonight the Honolulu Fire Department has not yet determined cause, damages or whether the 4:14 a.m. fire was started intentionally.

Police, however, classified the case as an arson based on evidence of forced entry and interior search indicating a burglary. The fire was started in the trash can of a restroom, police said.

The fire gutted three classrooms, an office, store room and the teacher's lounge and displaced 48 preschool and kindergarten students. The fire also destroyed most of school's archives.

The thieves were unable to open a fireproof office safe containing proceeds from the school's recent fair, police said.

Ten fire companies responded to the alarm and had the fire under control at 4:45 a.m. However, as fire investigators sifted through the classroom remains at about 8:30 a.m., the fire reignited in the roof area and three engines were called back to the school.