The Canyon Fire ignited Thursday afternoon and grew to more than 7.6 square miles (19.7 square kilometers) by 11 p.m., according to the Ventura County Fire Department.

The fire is burning just south of Lake Piru, a reservoir located in the Los Padres National Forest. It's close by Lake Castaic, a popular recreation area burned by the Hughes Fire in January. That fire burned about 15 square miles (39 square kilometers) in six hours and put 50,000 people under evacuation orders or warnings.

Thousands of people are evacuating a wildfire in a mountainous area north of Los Angeles on Friday. CNN’s Nick Watt explains what communities are under threat and how firefighters are responding.