Sparks from a malfunctioning electrical utility pole caused a wildfire that spread from Kalihi to Fort Shafter yesterday, Honolulu fire officials said.

About 9:30 a.m. yesterday, sparks apparently fell from the transmission line, starting a fire at the base of the pole behind the parking lot of the Board of Water Supply base yard on Kini Place in Kalihi, said Honolulu fire spokesman Capt. Terry Seelig.

The small fire quickly spread across and over a mountain ridge to Fort Shafter, burning dry brush — tall grass and koa haole, kiawe and ironwood trees.

Some 70 city and federal firefighters responded to the blaze, including the Honolulu Department’s Air One helicopter and a private helicopter contracted by the Army.

The quick-moving fire approached Hauiki Homes, a public housing project on Meyers Street. Firefighters stopped the fire 30 yards from the fence line that borders the complex, Seelig said.

Resident Courtney Valdez said she thought someone was having a barbecue when she smelled smoke. But then saw black, feathery ashes in the air from the mountainside blaze.

By 3 p.m., firefighters had contained the wildfire, which charred 30 acres. Tradewinds helped spread the blaze, Seelig said.

However, the fire flared up again by early evening. Three fire companies battled the resurgent fire on top of the ridge above Fort Shafter and by 6:30 p.m. were expecting to have the fire back under control within half an hour.

There were no evacuations ordered.

Area power lines near the ridge were de-energized as firefighters battled the blaze. Hawaiian Electric Co. is investigating what caused the malfunction, said spokesman Darren Pai.