LOS ANGELES, July 30 (Xinhua) -- The toll in northern California's blaze has risen to six, officials announced on Sunday.

The wildfire in Shasta County in the western U.S. California State has destroyed more than 500 structures, scorched tens of thousands of acres, and forced thousands of people to evacuate.

According to County Sheriff Tom Bosenko, the charred remains of the sixth victim, who had ignored evacuation orders, were found in a gutted residence on Sunday.

Two children and their 70-year-old great-grandmother died in the wildfire that swept with devastating speed into the city of Redding, about 260 kilometers north of Sacramento, capital of California.

Two firefighters were also killed by the monster fire earlier this week.

So far this year, wildfires have scorched almost 1.7 million hectares across the United States, crossing the 1.5-million-hectare average for the same period in the last decade.