Canada wildfires leaves train 'encased in flames' as smoke from drifts towards US

Dramatic video shows a freight train in Canada surrounded by wildfire flames and workers requesting an emergency rescue as they report being "encased" in fire.

"This could potentially overtake us here, this has gotten a little scary," a crew member says as the train rushes past burning trees near Armstrong, Ontario.

There are more than 100 wildfires burning in the province, with several northwestern communities under threat. Smoke blanketed Toronto, which woke up to hazy skies and some of the worst air quality in the world.

The wildfires have led to concerns smoke will drift into US cities over the next few days - including in New Jersey, where Sunday's World Cup final is due to take place.

Canadian National Rail said in a statement that the workers who were trapped outside Armstrong were all safely rescued, and that operations have been temporarily suspended in the region.

The statement did not add any further details about how the rescue occurred.

There are currently 838 wildfires actively burning across Canada, according to the Canadian Interagency Forest Fire Centre.

Grand Council Chief Linda Debassige said in a statement on Wednesday that the remote Namaygoosisagagun First Nation in northern Ontario was "devastated by an unexpected and fast-moving wildfire" that severely damaged homes and community buildings.

More than a dozen fires are also burning in Minnesota, a US state on the Canadian border, due to extreme heat, dry conditions, and strong winds.

Officials have warned people to stay indoors to avoid the smoke, and to avoid strenuous activity and heavy breathing when spending time outside.

On Wednesday, residents of Canada's largest city, which has also faced extreme heat this week, woke up to a yellow sky, and warnings from Toronto officials about the dangerous air quality.

IQAir, a company which tracks global air quality, ranked it as having the worst air quality in the world.

It was ranked ahead of Kinshasa in the Democratic Republic of the Congo, Delhi, Dubai, and Jerusalem.

Outdoor World Cup fan events for the England and Argentina match on Wednesday were cancelled in the city, and wading pools closed.

In the US, officials have warned that the smoke is expected to drift into the region starting on Wednesday, even as the extreme heat starts to ease.

Extreme heat warnings in the midwestern states of Wisconsin and Minnesota are expected to expire by Thursday night.

But air quality will remain an issue for millions, especially for children, the elderly, or those with health conditions.

"You may experience mild and common symptoms such as eye, nose and throat irritation, headaches or a mild cough," Environment Canada warned.

"More serious but less common symptoms include wheezing, chest pains or severe cough. If you think you are having a medical emergency, seek immediate medical assistance."

Officials say the smoke will not be as bad as it was in 2023, when smoke from Quebec wildfires blanketed the US East Coast.

"At this time, current forecasts do not indicate a repeat of 2023 conditions," wrote New York City Emergency Management in a statement on Tuesday.

The statement added that KN95 masks will be distributed for free at public library branches around the city.