The fire was declared contained about 6:30 last night after burning approximately 150 acres toward the back of Nanakuli Valley.

"It was contained to a ravine toward the back of the valley when everybody went home last night," said Capt. Emmit Kane, a spokesman for the Honolulu Fire Department. "The winds shifted over night and the fire started migrating down the valley," Kane said.

Fire crews kept watch throughout the night, but at about 3:45 a.m. today, 11 fire companies and four tanker trucks were recalled to deal with the flare-up.

"They ran hoses between some of the homes in the upper valley where the flames came within about 100 yards," Kane said.

The fire burned about 150 acres before it was contained yesterday evening and burned an additional 100 acres this morning, Kane said.

"Right now, our primary concern is that the smoke from the fire might make breathing difficult for people with pre-existing breathing problems such as asthma," Kane said. "The winds are light and variable and so far, the smoke is drifting makai but is passing over the roof tops of the home farther down in the valley."

By about 9 a.m. there had been no emergency calls for fire or emergency crews to assist people with breathing difficulties, Kane said.

He said firefighters around the island are bracing for what could be a summer rife with brush fires.

"There was a lot of rain over the winter months and the vegetation really took off," Kane said. "After just a few weeks of relatively dry weather, that abundant vegetation has already started to dry out and is becoming a problem."