A fire at the Kaiaka Beach Park restroom in Waialua Saturday afternoon is believed to be intentionally set, said Honolulu Fire Department spokesman Capt. Terry Seelig.
The fire happened at 1:56 p.m. and was under control by 2:35 p.m.
The fire started in one of the bathroom stalls, Seelig said.
Damage to the wooden roof is estimated at $100,000.
Fire investigators forwarded the case to Honolulu police.