A wildfire that ignited Sunday afternoon and grew to 800 acres within just a few hours was threatening the San Francisco bedroom community of Clayton, where state authorities ordered the evacuations of dozens of homes on Sunday night.
The Morgan Fire was first reported at 1:15 p.m. (4:15 p.m. ET), and by 7:30 p.m. it was already burning about 800 acres on the edge of Mount Diablo State Park, in Contra Costa County about 15 miles northeast of San Francisco, according to an incident report from the California Department of Forestry and Fire Protection, or CalFire.
Twenty-five fire engines, four air tankers, three helicopters and more than 175 firefighters rushed to the scene, but the fire was still growing, and it was only about 10 percent contained Sunday night.
CalFire ordered mandatory evacuations for Oak Hill Lane, Curry Canyon and Curry Point in and around Clayton, a community of 11,000 people. Fifty to 75 homes were threatened by the swiftly moving flames, it said.
"Leave now by car," the Contra Costa County Sheriff's Office said in an advisory marked as "urgent" about 6 p.m. "... Stay off the phone unless you need to report a life-threatening emergency at your location."
An enormous plume of smoke was visible for miles — even at Candlestick Park, where the San Francisco 49ers were playing their opening game, the Contra Costa Times reported.
"This thing grew pretty quickly," resident Dave Miller told the newspaper. "Now the wind is picking up. It could get ugly."
Authorities had no immediate indication of the cause of the fire.