 A wildfire in Hawaii's central Oahu has grown to cover more than 2.5 square kilometers in a remote mountainous area and has burned native koa and ohia trees, officials said Tuesday. No structures or homes were threatened and no evacuations were ordered, multiple helicopters from the Honolulu Fire Department, the U.S. Army and the state-dropped buckets of water on the blaze from the air for a second straight day, Mililani and Wahiawa are the town's closest to the flames, but they weren't at risk. Many installations Schofield Barracks and Wheeler Army Airfield are also in the area, which is about about 32 kilometers north of Honolulu and firefighters battled flames from the air because the terrain is rough and inaccessible. The fire was moving east on a ridge and was 30 percent contained by mid-afternoon Tuesday, the Honolulu Fire Department said in a news release, the fire burned through heavy timber and native vegetation, the state said.