LAKEHEAD (CBS SF) — A small army of firefighters battled the Salt Fire Sunday, raging in the tinder-dry forest and chaparral brush of the Shasta-Trinity National Forest, expanding containment to 15 percent overnight as the burn zone grew to more than 9,100 acres.

U.S. Forest Service officials said the fire, which roared to life on Thursday, has destroyed 27 homes and 14 outbuildings — mostly in the Gregory Creek Acres neighborhood.

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Among those who lost their homes was Darlene Sherill of Danville.

“It feels very much like a violation to have a fire come to your home and destroy it, probably within minutes,” Sherrill told the San Francisco Chronicle by phone from a Redding hotel on Friday.

Evacuations remained in place Sunday for several local small communities.

“(There is) immediate threat to life and property in the communities of Lakehead, Pollock and Riverview,” the forest service said in a release.

There were 731 firefighters on the line as the blaze moved into the Campbell Creek area and toward Crane Mountain.

Authorities suspect the Salt Fire ignited from a hot piece of metal flew off a car or truck on Interstate 5 but they haven’t found the vehicle.

Severe to extreme drought conditions have left the heavily wooded region extremely vulnerable to wildfires.

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“Fuel conditions this year are looking a lot more like late August than early July,” said Adrienne Freeman, a spokeswoman for Shasta-Trinity National Forest.

The Salt Fire was just one of the three major blazes burning along the I-5 corridor in Northern California.

The largest blaze, the Lava Fire was burning partly on the flanks of Mount Shasta and was 39% contained after growing to more than 37 square miles.

The blaze, caused by a lightning strike, forced several thousand people from their homes but most were allowed to return late Thursday.

The Tennant Fire in the Klamath National Forest has burned five buildings, including two homes, and threatened several hundred more. It grew slightly to more than 15 square miles but progress was also reported there and it was 29% surrounded.

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Mop-up began on the western flank while the east side remained active. Evacuation orders and warnings continued in nearby areas.