CLAYTON (CBS SF) — Firefighters are continuing to tackle the Morgan Fire on Mount Diablo as containment reached 70 percent Wednesday, a Cal Fire spokeswoman said.

“Today’s focus is on keeping that containment,” Cal Fire spokeswoman Tina Rose said. The fire has burned an estimated 3,133 acres since it was first reported around 1 p.m. Sunday.

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The fire initially started off of Morgan Territory Road near Mount Diablo State Park, southeast of Clayton.

“It’s no longer spreading,” Rose said. “It’s not getting bigger.”

Full containment is expected Friday.

However, she cautioned that “all it takes is one little gust of wind” to spark a new fire from smoldering embers.

She said there are still burning tress, brush and other debris along the slopes of the mountain.

“Any little spark is going to spread quickly on that mountain,” Rose said.

Hot temperatures, dry conditions and wind have been complicating battling the wildfire, she said.

Alongside fire suppression efforts, crews are working on rehabilitation, Rose said.

She said the blaze has burned off vegetation that can lead to erosion once the rains arrive.

She said re-seeding, tree planting and other forest remedies will be part of a long process that needs to start immediately.

“It’s not going to be very long until the winter rains start coming,” she said.

Evacuations had been ordered Sunday, and as many as 100 homes were threatened by the flames, according to Cal Fire. On Tuesday around 6 p.m., the evacuation orders were lifted and all residents were able to return home.

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Roads on the eastern side of the mountain that had been closed because of the fire have reopened, according to Cal Fire.

Rose advised residents that crews are still battling the fire and roads may get clogged.

She said residents should expect to be sharing the road with large equipment.

“Please slow down and be patient,” Rose said.

More than 1,370 fire personnel from more than a dozen agencies responded to the fire. Some crews were starting to leave the area this morning as the fire died down.

Three firefighters suffered minor injuries battling the blaze, and one communications shed was destroyed, Rose said.

Other infrastructure, such as communication towers on the peak of the mountain, was spared, Rose said.

The cause of the wildfire is under investigation.

A smoke advisory issued by the Bay Area Air Quality Management District remains in effect Wednesday, air district spokesman Tom Flannigan said.

He said the advisory would likely remain in effect “as long as there are flames.”

The advisory is a reminder for residents, especially those in Contra Costa and Alameda counties, that air quality is compromised by smoke from the blaze.

The air district has advised residents, especially those with respiratory problems, to limit their outdoor exposure.

Flannigan said there have been no reports of residents suffering health problems because of the smoke.

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