The Hawaii Department of Land and Natural Resources has spent at least $53,500 helping to fight the brush fire in Makakilo
DLNR estimates that it cost $43,000 to contract helicopters over two days to make water drops. Another $10,500 went to firefighting personnel.
The Honolulu Fire Department does not have estimates on overtime costs, if they were incurred. Fire officials say most of the personnel used were already on duty.
On Tuesday, Honolulu firefighters battled the leading edge of the stubborn forest fire.
A department spokesman says the fire is burning in thick underbrush along the upper slopes of the Waianae mountain range near Polihale Ridge. A ground crew was flown into the site and was fighting the blaze with picks, shovels and chainsaws.
The fire department spokesman says the fire has not grown and remains 20 percent contained on the upper slopes.
Investigators say two 7-year-old brothers playing with a lighter started the flames Friday afternoon. They will get a personalized education on fire safety.