A huge fire in and around California's Yosemite National Park has continued to spread and now covers almost 230 sq miles (600 sq km), officials say.
The Rim Fire is now raining ash on a key reservoir that supplies water and hydro-electric power to San Francisco.
City officials say they are moving water to lower reservoirs and monitoring supplies for contamination. The blaze is also threatening thousands of homes and some of California's renowned giant sequoia trees. On Monday officials said the fire was 15% contained after burning for more than a week - up from 2% containment on Friday. Strong winds are making the fires more difficult to control.
"This fire has continued to pose every challenge that there can be on a fire," said Daniel Berlant of the California Department of Forestry and Fire Protection. The blaze began on 17 August in the Stanislaus National Forest but the cause is still unknown. Trevor Augustine from Unified Rim Fire Command Group outlines the conditions facing fire crews Some 2,800 firefighters are tackling the flames in difficult terrain.
Evacuations, some voluntary and some mandatory, are taking place. Despite the threat to some 5,000 homes, only a few have been destroyed