'Rocky Fire' scorches California

The blaze, dubbed the "Rocky Fire," erupted in the inland area of the North Coast Ranges in California, about 110 miles (177 kilometers) north of San Francisco. It is the biggest of more than 20 wildfires currently raging across the drought-stricken state after thousands of lighting strikes hit in recent days.

The blaze has scorched 62,000 acres (25,090 hectares), quadrupling in size within just a few days. On Saturday night, the fire burned through 20,000 acres in a single five-hour period. That's an "unprecedented historical rate of spread," according to Daniel Berlant, a spokesman for the California Department of Forestry and Fire Protection.

More than 9,000 firefighters, many of them reinforcements from other states, are struggling to keep pace with the blaze. Strong winds on Monday night helped the fire jump a state highway that had served as a containment line.

The fight to contain the blaze is being waged on the ground and in the air. Nineteen water-dropping helicopters and four airplane tankers have been deployed to dump water and flame retardant in an effort to stop the fire from growing.

More than 13,000 people have been urged to leave their homes for evacuation centers. Here, residents of Spring Valley, a community under mandatory evacuation orders, watch on as the "Rocky Fire" advances near the community of Clearlake Oaks.

More than 50 buildings have been destroyed by the fire so far, and thousands more are under threat. Clear Lake resident Wayne Fischer stands amid the rubble of his home, which was burned to the ground.

According to state figures, 121,000 acres (49,000 hectares) of land has been burned by fires so far in 2015. Although wildfires aren't uncommon in California, this year has been particularly bad due to extremely dry conditions caused by a four-year drought.