Honolulu fire officials say the brush fire in Makakilo was about 100 yards away from communication towers and a few structures in the area on Monday.
Fire crews are making it a priority to protect these areas and have pre-treated the surrounding area with foam to absorb heat and protect structures.
Their main strategy is to establish a break between the fire and the Honouliuli Forest Reserve.
Three state helicopters were used for water drops in addition to the HFD chopper. The brush fire in Makakilo has been going on for more than a week.