A growing wildfire in California is threatening the largest grove of giant sequoias in Yosemite National Park. The Washburn Fire has doubled in size over the past 24 hours, and it is now estimated to have burned 1,591 acres. Firefighters are working in difficult terrain to protect some of the largest and oldest redwood trees in the world. Residents and campers near the fire have been evacuated, and thick smoke has worsened the region’s air quality and obscured the park’s scenic views. The blaze, which started on 7 July, threatens at least 500 giant sequoias in the Mariposa Grove, including the famed Grizzly Giant which is thought to be around 3,000 years old. For now, none of them have been destroyed by the fire. The Yosemite fire and aviation management department said it was “proactively protecting” the grove by setting up a sprinkler system to increase humidity around the trees and by removing potential fuels from the site.(BBC)…[+]