Extremely dry and windy conditions in the American West have led to the explosive growth of several wildfires in the last few days, which have quickly grown and spread enough to endanger major area towns. More than 100 wildfires are burning in the region.

Cal Fire warned in a Wednesday update that the Caldor Fire, which was sparked on Saturday, had experienced “unprecedented fire behavior and growth due to extremely dry fuels pushed by the south west winds,” tripling in size overnight from Monday into Tuesday and swelling to a conflagration consuming some 53,000 acres.

California Governor Gavin Newsom declared a state of emergency on Tuesday in El Dorado County, which is downwind of the fire, after it destroyed the town of Grizzly Flats, which had been home to 1,200 people.