Massive wildfires sweeping through California have killed at least 26 people and damaged thousands of homes, businesses and other buildings, authorities said. Firefighters were still battling 22 wildfires in multiple counties as of Thursday morning. Intensified by strong winds, the flames have charred more than 170,000 acres of land, damaged or destroyed at least 3,500 structures and forced nearly 20,000 residents to evacuate, according to the California Department of Forestry and Fire Protection. The causes of the fires are unknown.