Honolulu police have opened a first-degree arson case for the fire that heavily damaged the historic Central Union Church Preschool and Kindergarten Wednesday morning.

The fire started at about 4:10 a.m. and destroyed five rooms and an office at the more than 100-year-old facility at Punahou and Beretania streets. Classes were canceled until next week.

Police said the fire was “;set intentionally by an unknown person,”; but also said the cause of the fire was under investigation. The fire caused more than $100,000 in damage, according to police.

Meanwhile, firefighter investigators will continue searching today for the cause of the fire and a damage estimate.

Honolulu fire Capt. Terry Seelig said it is the first time he has heard of HPD opening an arson case before the Fire Department completed its investigation.