CALIFORNIA FIRE 'SERIOUS THREAT' !
Firefighters tackling an intense wildfire north of Los Angeles say the blaze remains "very dangerous".
Fuelled by hot weather and dense, dry brush, the blaze is threatening 12,000 buildings and key communications masts.
Two firefighters were killed on Sunday after their vehicle was overrun by flames and rolled down a mountainside.
Mike Dietrich, of LA County Fire Dept, said: "We are making progress. But it is... slow and very dangerous. We have to wait for the fire to come to us."
The fire has been growing steadily, doubling in size on Sunday. Mr Dietrich said it was possible it would double in size yet again over the next few days.
See map of California wildfires
Some 6,600 homes are under mandatory evacuation orders. State Governor Arnold Schwarzenegger described the blazes as "still totally out of control".
The fires also threaten communication towers housing transmitters for all Los Angeles' major TV stations.
Mount Wilson, where the towers are located - near the city of Pasadena - is also home to a historic solar observatory.
In pictures: California's wildfires
Firefighters are on the mountain clearing brush and spraying fire retardant in preparation for the fires, which are approaching the transmitters.
About 2,500 firefighters are trying to contain the fires, which have burnt over 66 sq miles (170 sq km) of forest.
Fire department officials say the area's steep, rugged hills are making efforts to fight the fire more difficult.
With forecasts of continuing hot weather, there has been speculation that it could take firefighters a week to bring the blaze under control, says the BBC's David Willis in Los Angeles.
Wildfires are a feature of the Californian summer, but it is unusual for them to break out so close to major population centres.
A number of other fires are also burning in southern and central California.
A new fire in Placer County, north-east of the state capital, Sacramento, has destroyed 60 structures, many of them homes in the town of Auburn.
BBC NEWS REPORT.