A plane makes a retardant drop on a ridge on Aug. 2 at the Apple Fire north of Banning in Riverside County, which "doubled in size" on Aug. 1, per KTLA. Robert Gauthier / Los Angeles Times via Getty Images

A massive wildfire that prompted mandatory evacuations in Southern California over the weekend burned 26,450 acres and was 5% contained by Monday afternoon, the California Department of Forestry and Fire Protection said.

The big picture: As California remains an epicenter of the coronavirus pandemic in the U.S., some 15 separate fires are raging across the state. About 7,800 people were under evacuation orders from the Apple Fire, about 75 miles east of Los Angeles, as hundreds of firefighters battled the blaze. CalFire said Monday that a malfunction involving a "diesel-fueled vehicle emitting burning carbon from the exhaust system" started the Apple Fire.

A firefighter from Carpinteria monitors a flare-up along a ridge as the Apple fire burns north of Banning in Cherry Valley, California, on Aug. 1. Photo: Gina Ferazzi/Los Angeles Times via Getty Images
The Apple fire burns further into national forest territory in Cabazon, California, behind Morongo Casino. Photo: Josh Edelson/AFP via Getty Images
A 747 Supertanker makes a retardant drop on a ridge at the Apple Fire on Aug. 1. The National Weather Service has issued an excessive heat warning for Southern California, with temperatures between 96 and 106 degrees Fahrenheit. Photo: Josh Edelson/AFP via Getty Images
Firefighters wait in an open field as flames make their way across a hillside during the Apple fire. Photo: Josh Edelson/AFP via Getty Images
A firefighter walks back to his truck near a pyrocumulus ash plume near Banning on Aug. 1. Photo: Josh Edelson/AFP via Getty Images
A firefighter watches the flames crest a ridge at the Apple Fire on Aug. 1. Photo: Josh Edelson/AFP via Getty Images
A plume of ash towers above Banning on Aug. 1. Photo: Josh Edelson/AFP via Getty Images
Ash from the wildfire over a billboard in Banning on Aug. 1. Photo: Josh Edelson/AFP via Getty Images

Editor's note: This article has been updated with the latest details on the fire and more photos.

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