Satellite images show plumes of smoke from Canadian wildfires moving across the U.S. Midwest towards the East Coast on Wednesday. Tens of millions of people remain under air-quality alerts.

Eight firefighters died while 230,000 people across Canada were evacuated from their homes, the Canadian government said. Wind pushed smoke from the wildfires toward the U.S., enveloping New York ...

Air quality in Western Pennsylvania dropped to unhealthy levels Wednesday and could remain that way until at least Sunday as smoke from Canadian wildfires continues to pollute the Northeast.