Calmer winds helped crews fighting a massive wildfire set by arsonists that killed four firefighters and critically injured a fifth in the canyons of Southern California.
"It looks like things are beginning to turn in our favour. We had a good overnight. It wasn't nearly as windy as it's been," said California Department of Forestry spokesman Bill Peters.
Now in its third day, the fire that broke out in uninhabited brushland about 90 miles (145 kilometres east of Los Angeles had blackened 39,900 acres (16,000 hectares), or more than 62 square miles (159 square kilometres, and was 40% contained, authorities said.
A reward for information leading to the arsonist reached $500,000 on Friday, as $100,000 posted by Riverside County quickly multiplied with matching offers from the state, neighbouring San Bernardino County, Rancho Mirage resident Tim Blixseth and the Morongo Band of Mission Indians.
Forecasters predicted winds would ease and temperatures would drop slightly throughout the weekend, which could help as crews work in steep terrain to build fire breaks around the blaze.
Investigators are looking into whether the wildfire was related to other blazes in recent months, including a canyon fire last weekend, though a sheriff's spokesman said there was no immediate indication of a serial arsonist.
Residents said they saw two young men leaving the area where the fire broke out west of the San Jacinto Mountains.
The fire destroyed about 10 structures, including homes, forced 700 people to flee, and flushed coyotes and other wildlife into the open.
The firefighters died on Thursday when the wind blew a wall of flames down on them in the hills near Palm Springs as they tried to protect a home.
Investigators have not said how they know the blaze was arson, though they said those responsible could face murder charges.
AP