The vegetation fire, which has been dubbed the Canyon Fire 2, prompted the evacuations of more than 5,000 homes in Anaheim Hills, Orange, Orange Park Acres and Tustin on Monday.
The northern California fires have been fanned by unexpectedly fast winds and a lack of humidity, according to California Governor Jerry Brown.
One firefighter sustained a minor smoke-inhalation injury, authorities said.
Orange High has followed Canyon and postponed all outdoor activities Tuesday because of Canyon Fire 2 in the Anaheim Hills.
The Sonoma County Sheriff's Office says deputies were dispatched to help firefighters and California Highway Patrol officers with evacuations. By late afternoon, ash from the fire was falling as far away as Long Beach and San Pedro.
That smoke could be seen from around Southern California, from inland areas to Disneyland and the coast.
The couple's granddaughter, Ruby Gibney, told Oakland television station KTVU (http://bit.ly/2kCV4Vz ) on Monday that their home was quickly ravaged by the fire and they were unable to get out. At least four homes were completely gutted by the flames.
At least 10 people are reported dead, around 100 injured and at least 1,500 homes and businesses have already been destroyed. As of 3:30 p.m. October 9, the fire is 0 percent contained, according to the Orange County Fire Authority's website.
The evacuation zone was primarily for residences in the wildland-urban interface south of the 91 Freeway and east of the 241. An information hotline was set up at (714) 765-4333.
A state of emergency was issued for Orange County by Gov.
"The fire was fairly inactive last night on the western edge, but was still active on the eastern edge of the fire", Wyatt said. MORE: Full list of evacuation orders, road closures for Canyon Fire 2Gov.