Polipoli, USA — While its considered almostimpossible for a cigarette to ignite a brush fire in Hawaii, a state forestryofficial said Friday that the environmental conditions were ripe for the firethat burned hundreds of acres of forest near Polipoli Springs State RecreationalArea.
The fire, which started Jan. 23, wasfinally contained on Monday after it had swept across 2,291 acres in the KulaForest Reserve. As the rain that had helped douse the fire cleared Friday, stateforestry workers remained on scene looking for hot spots.
Wayne Ching, state protection forester for the Division of Forestry andWildlife on Oahu, said it was the first time he could recall a wildfire on stateland that was determined to have been started by a cigarette.
People need to know its very rare, said Ching, who oversees thewildland program for the state. But people still need to be cautious. Therealways is that possibility.
Ching, Maui district resource and protection forester Lance De Silva andKauai forester Kawika Smith made up the state investigative team that identifiedthe cause of the fire.
At the fire scene Tuesday, the investigators talked to a forestry worker whohad been among the first to respond to fight the fire.
He told us how large the fire was when they got there, Ching said.
Using that information, along with signs including charring on vegetationthat helped indicate the direction the fire traveled, the investigators narrowedthe origin of the fire to an area the size of a desktop, Ching said.
Then they got down on their hands and knees to look for the source. Thecigarette butt was very, very obvious, Ching said.
Everything was black and the butt was burned on one end but still white,he said.
The cigarette butt was found on the upper Waiohuli trail about 150 feet fromthe access road.
While investigators can usually determine where a fire started, it isnt aseasy to find the device that ignited a fire, Ching said. Often, he said, thetask is difficult because firefighters spraying water or moving earth toextinguish a fire may also wash away evidence of how the fire began.
But at Polipoli, he said firefighters were probably focused on hotter areasaway from where the fire started, leaving the area of origin intact. He said theon-scene investigation took about an hour.
Investigators also reviewed records from a remote weather station about ahalf-mile away at Polipoli.
In Hawaii, relative humidity has to be around 28 percent for a cigarette toignite a fire, Ching said.
Its almost impossible, he said.
But weather records showed that when the fire started, the relative humiditywas measured at 32 percent, falling within the range of possibility.
The conditions were very, very dry, Ching said, noting that the lowrelative humidity was a big factor in the fire. There was probably enoughheat in that cigarette to set off some combustion or ignite some of the brushthat was there.
He said the investigators considered relative humidity as well as temperature,wind speed and direction and dryness of material to burn. The factors added upto strong evidence that the cigarette started the fire, Ching said.
With pockets of unburned terrain within the 16-mile fire perimeter, the areaactually burned is estimated at 1,700 acres.
The forest and Polipoli state park remains closed while firefighters continuemop-up work and assess the threat from trees and branches killed by the flamesfalling over onto roads and trails.
Maui District Forestry Chief John Cumming said the weather cleared in thefire area Friday, following four days of steady rain.
We will be keeping an eye on it over the weekend as things warm up and dryup, Cumming said.