More than 20,000 people were ordered to evacuate several Sierra foothills towns near Chico on Thursday as a wildfire raged out of control and grew to more than 8,000 acres in just seven hours. Law enforcement has reported that some residents and sheriff’s deputies are trapped inside the perimeter of the conflagration. The blaze is still burning in multiple parts of Paradise, an incorporated town of about 27,000 that is home to many retirees and lies about 10 miles east of Chico in the foothills north of Sacramento. The fire has sent dark clouds of smoke over Chico and as far south as the Bay Area. A smoke advisory has been issued for the Bay Area through Friday. Residents may see or smell smoke from the Camp Fire.