Three large wildfires in northeast Washington that have forced tens of thousands of evacuations, destroyed homes and damaged some 1,000 other structures continued to rage Aug. 5.Firefighters from across the state continued to battle the Old Trails Fire, Fairview Fire and Autumn Lane Fire, which have burned more than 10,500 acres in the Spokane area. Mandatory evacuations also remained in effect for much of the region.As of the afternoon of Aug. 5, the Spokane County Sheriff's Office reported, the Autumn Lane Fire remained the most active of the three incidents."Despite heightened fire danger, firefighters successfully held the fire within its established footprint Tuesday while completing and reinforcing containment lines around the perimeter," the agency wrote in a social media post.The sheriff's office also said the three fires had reached the following containment levels.Autumn Lane Fire: 13% containedOld Trails Fire: 13% containedFairview Fire: 5% containedHere's the latest update on the fires.What started the fires?It was not immediately known what started the Autumn Lane or Fairview fires, which both remained under investigation Aug. 5, according to the sheriff's office.But officials on Aug. 3 said they arrested a man on a first-degree arson charge in connection to the Old Trails Fire.Man arrested on arson charge set to be arraignedAaron F. Farinacci, a 37-year-old Spokane man arrested on a single arson charge, made an initial appearance in court Aug. 4, USA TODAY previously reported.He was set to be arraigned on the charge Thursday, Aug. 6.National Guard responds to Spokane streetsA day earlier, Washington National Guard Maj. Gen. Gent Welsh said there were more than 100 National Guard members serving on Spokane streets.“Every one of those National Guard members is a volunteer and everyone of them is here to assist you,” Welsh said during a news conference.Natalie Neysa Alund is a senior reporter for USA TODAY. Reach her at nalund@usatoday.com and follow her on X @nataliealund.