High winds continued to fan a massive brushfire upslope of Ma'alaea yesterday, bringing the number of acres burned since early Friday to 3,423, a Maui County spokeswoman said.

"It's a healthy fire," Maui spokeswoman Ellen Pellisero said. "Everybody's saying this is the biggest brushfire ever for us."

The fire started about 1:30 a.m. Friday north of Ma'alaea Harbor, fire officials said. Winds upward of 30 mph spread the flames, forcing the closure of Honoapi'ilani Highway late Friday.

How the fire started is still under investigation.

Last night, the flames were threatening three Maui Electric Co. transmission lines, which feed West Maui.

Shane Murayama, a MECO dispatch supervisor, said two of the lines were de-energized yesterday because the fire was creeping closer. The remaining line was feeding homes last night.

Murayama also said it's not clear whether the lines sustained any damage. A MECO supervisor was watching the flames last night, just in case the third line also needed to be turned off.

"It's burning at a steady pace," Murayama said.

Four helicopters and 75 firefighters fought the wildfire yesterday, and firefighters remained on the ground last night.

Pellisero said the high winds and hilly terrain make the fire unpredictable — and hard to fight. "It's moving up and down and around," she said. "It's just so chaotic."

The blaze is at an elevation of between 2,000 and 4,000 feet, and is burning mostly scrub and low brush. At about 2,400 feet, the flames branch off toward Olowalu, Pellisero said.

The fire has threatened no homes and caused no injuries.

But the closure of Honoapi'ilani Highway on Friday because of smoke stranded residents and tourists for hours.

About 74 people showed up at a shelter at the War Memorial Gym on Friday, and 20 stayed overnight.

State Civil Defense officials are monitoring the blaze and will open additional shelters if needed.

Reach Mary Vorsino at mvorsino@honoluluadvertiser.com.