Hawaii's governor on Friday declared an emergency on the island of Maui, where firefighters were battling a blaze that has forced the evacuations of thousands of people and sent huge clouds of smoke billowing over nearby beaches. The fire on Maui, sometimes called the Valley Isle, has scorched more than 10,000 acres (4,000 hectares) of former sugar cane fields and brush since erupting on Thursday, and by Friday was 20 percent contained, island officials said in a statement. The blaze began in the island's central valley, and steady winds of up to 20 miles per hour (30 kmh) stoked the flames, officials said.