NANAKULI — Firefighters struggled yesterday to contain a frustrating brushfire that had burned more than 2,000 acres in Nanakuli, closing schools and roads, and singeing several species of native plants.

Late last night, crews scrambled to the Kahe power plant, where the fire had flared again and was threatening about a dozen homes, said HFD spokesman Capt. Emmit Kane.

The fire was about a quarter-mile from the homes and moving toward them, Kane said. "It's not a dire situation yet, but the first priority is to protect property."

The fire was also near diesel storage tanks at the power plant, but they apparently were in no immediate danger, he said.

Around 10:30 p.m. the flames were so bright behind the power plant that it looked like the sun was coming up over the ridge.

"This one is pretty much getting close to either eclipsing or surpassing the biggest fire this year," Kane said. "It's requiring a lot of resources and also hindering the response time for other parts of the island."

"This fire is far from being controlled," he said.

Crews were expected to monitor the fire all night.

Farrington Highway had to be closed around 9:15 p.m. near the plant, and traffic was backed up all the way to Pearl City. But by 9:50 the townbound lanes had begun to move and by 10:30 all lanes had been reopened.

More than 100 firefighters, 16 fire engines, four tankers, and the Air One helicopter — roughly one-quarter of the Honolulu Fire Department's resources — engaged the blaze on four fronts by 5 p.m. yesterday. More than 25 federal firefighters, four military helicopter pilots and another from the state Department of Land and Natural Resources were working with HFD to contain the fire, which had burned more than 2,000 acres.

"It was like a volcano," said Edwin Wright, a 29-year-old Nanakuli resident. "You know, like lava coming down the mountain."

By early evening residents were hosing down the roofs of their homes and gathering in the streets as smoke rolled through the streets, forcing residents to pull their T-shirts over their mouths and eyes. A blanket of thick, black smoke settled over the neighborhood as about 50 firefighters defended homes.

"I will not leave my property. If it consumes everything it will have to consume me with it," said May Wright, 74, who sat outside her home with a white cloth held over her mouth as flames crept down a hill nearby.

The fire started at about 1:30 p.m. Sunday, about 200 yards from the ridge line on the west facing hillside of Nanakuli Valley. Kane said the blaze does not look like it was intentionally set because it started on a steep slope. Kane said power lines running from the valley floor to the top of the ridge are being looked at as possible ignition sources.

Firefighters focused their efforts yesterday afternoon on the Palehua ridge line where one of the fire's four fronts threatened a forest and came within a mile of Camp Timberline. The high-altitude location and rugged terrain prevented firefighters from attacking the blaze on foot. Instead, helicopters made water drops as 30 firefighters waited nearby.

"There is a scattering of homes up there so we're concerned about that," Kane said. "If the fire is able to take hold in the forest area, that presents a different challenge."

Firefighters had fought the expansive fire yesterday at the back of Nanakuli Valley, at Waimanalo Gulch and along the Palehua ridge line until nightfall. They had also battled it at Kahe early in the day only to have it reflare last night.

The fire and smoke were so intense authorities shut down Farrington Highway for hours yesterday morning, stranding motorists and forcing the military and O'ahu Civil Defense to open Kolekole Pass to civilian traffic a little after 10 a.m. Billowing plumes of smoke swept through Nanakuli Valley, forcing the closure of Nanakuli High and Intermediate School.

It is the second time in four months that the valley has burned. In May, firefighters fought a deliberately set fire that burned more than 3,000 acres in more than a week.

Officials with the Nature Conservancy and the Department of Land and Natural Resources monitoring the fire worried that the blaze could harm the 90 native and endangered species that live in Nanakuli Valley. Initial reports indicated that some species may have been burned.

Pat Costales, O'ahu branch manager for DLNR's division of forestry and wildlife, said two scouts were hiking through the valley and keeping an eye on areas known to house native plants.

He said a helicopter contracted by DLNR was assisting fire crews with water drops.

"I'm holding hope because the last Nanakuli fire stopped (before native plants burned)," he said. "There are a few small isolated populations of native plants within (the fire's) perimeter and there may have been at least one population overrun."

Pauline Sato of the Nature Conservancy said initially she was concerned when the fire got within a mile and a half of one of the conservancy's reserves.

Campbell Estate contracted a private helicopter that flew in from Maui yesterday to help with the water drop effort, she said.

"We coordinated with the Fire Department and the state to have the helicopter assist with this fire but if need be it will be used to protect the conservancy and estate land," she said.

Residents said they were wary of the fire but had grown accustomed to the annual blazes that, along with the heat, are hallmarks of summertime.

"It can be kind of scary but I'm kind of used to it," said Becky Dalere, 61, who has been a Nanakuli resident for 26 years. When she came home Sunday night, she saw the ridge engulfed. "There was just a lot of smoke and the whole side of the mountain was flickering.

"This was one of the worst fires I've seen."

Reach Peter Boylan at pboylan@honoluluadvertiser.com.