More than 400 homes and other buildings were destroyed Sunday by Northern California wildfires. Authorities are investigating reports that a civilian was killed as the fire spread to 50,000 acres—or 75 square miles. In one town, residents who ventured past police barricades said as much as half the municipality was gone. A second fire near Stockton destroyed about 200 structures. The two fires have displaced some 23,000 people. At least one person has reportedly died.