PAISLEY, Ore (CBS SF/AP) — There was a new challenge Thursday for the small army of firefighters battling the massive Bootleg Fire burning in a remote southern Oregon wilderness just north of the California border — a COVID-19 outbreak among the crews.

Fire officials said at least nine firefighters have tested positive for COVID and dozens of others are awaiting the results of their tests.

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“In accordance with protocols developed in partnership with the Oregon Health Authority for the 2020 fire season, individuals reporting symptoms and those who worked closely with them are tested and isolated until results are received,” officials said on the Bootleg Fire Facebook page. “Those who test positive are quarantined away from the fire camp.”

Meanwhile lower winds and better weather were helping the crews using bulldozers and helicopters gain a larger foothold on the fire.

The blaze grew to 624 square miles overnight — over half the size of Rhode Island — but containment had increased to 38 percent.

The fire also was approaching an area burned by a previous fire on its active southeastern flank, raising hopes that a lack of fuel could reduce its spread and the forecast was for favorable firefighting weather again Thursday.

“Fire crews and support personnel have made significant progress in containing this fire in the last few days,” Joe Prummer, incident commander trainee of Pacific Northwest Incident Management Team 2, said in a statement. “However, we still have a long road ahead of us to ensure the safety of the surrounding communities.”

The Oregon fire, which was sparked by lightning, has ravaged the sparsely-populated southern part of the state and had been expanding by up to four miles a day, pushed by strong winds and critically dry weather. The blaze was being fought by more than 2,200 people.

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At least 2,000 homes were ordered evacuated at some point during the fire and an additional 5,000 were threatened. At least 70 homes and more than 100 outbuildings have burned but no one is known to have died.

Firefighters continued to battle the flames as they have roared into the Sycan Marsh Preserve. Fire spokesman Terry Walter said the remained a focal point of the firefight on Thursday. Nearly 20 square miles of the preserve has already burned.

Meanwhile, Klamath County officials said they have received some good news from firefighters.

“We do know that they (the firefighters) have made a special effort to protect the Mitchell Monument, where the balloon bomb explosion occurred 76 years ago and we are so grateful,” said museum director Todd Kepple.

According to the Oregon Secretary of State’s website, the monument marks where Rev. Archie Mitchell and his wife took Sunday school children for a picnic east of Bly in 1945 when all were were killed except Mitchell by the explosion of a Japanese bomb.

They were the only Americans killed by an enemy strike during World War II on the American mainland.

“This site is nearly sacred to our local people,” Kepple said.

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