On 02/09/16 at 7:30 p.m., firefighters responded to a smoldering brush fire in the area of mile post 26 on Piilani Highway, in Kahikinui.
Kula firefighters arrived at 8:13 p.m. and found a 50 by 60 foot area of smoldering grass at the same site of a previous 25 acre brush fire on November 30, 2015.
Most of the grassy surface fuels had burned itself out, but there was evidence of an underground fire that firefighters found, up to two feet below the surface. Some areas were hot enough that you could not stand over it for very long. Organic matter such as roots below the surface can burn very hot, and for a very long time.
The cause of Tuesday’s fire is believed to be a rekindle of underground organic matter from the brush fire in November of last year. Although infrequent, it’s not uncommon to have an underground fire flare up days, weeks, or even months later. Firefighters in Lahaina have gone back to smoldering underground fires at the old Olowalu Landfill and near the Ukumehame Firing Range, 6 months to over a year later.
The Kula crew used a type of foam and water solution to cool the deep-seated fire. Class A foam is commonly used in firefighting. It can penetrate and absorb into non-metal combustible materials much more effectively than plain water. Firefighters soaked the ground with it, hoping to cool the smoldering organic matter enough to extinguish it.
Firefighters made periodic checks of the area looking for any signs of heat or smoke rising from the ground.