Air quality plummets as smoke from roaring wildfires chokes US west

Blazes in California, Washington and Oregon cause widespread damage as plumes travel across states and into Canada

California firefighters are battling large blazes across the state as the west's fire season heats up, covering swaths of Oregon, Washington, California and Canada in heavy smoke that has also traveled across the US.

Rain from tropical storm Kay brought relief to firefighters in southern California after a punishing heatwave gripped much of the state for more than a week and sent some crews to the hospital.