Emergency crews on Tuesday were racing to contain flames in the US Northwest, where a man was arrested on suspicion of arson in connection with the largest of the fires that have displaced tens of thousands. Aerial flybys revealed somewhere between 700 and 1,110 structures have been lost since the fires broke out over the weekend, authorities said. "I think from a historical standpoint, this is likely the worst natural disaster in Spokane's history," Washington Governor Bob Ferguson added. Ferguson declared a state of emergency on August 1, citing drought conditions and high temperatures exacerbating wildfires. The Washington State Department of Natural Resources also asked people to stop flying personal drones over the blazes.