Wildfires are burning in parts of the Western U.S. and Canada, forcing thousands of people to flee their homes

and forcing Canada to call up the military to help.

In addition to the physical devastation the flames are causing,

researchers are getting a clearer picture of just how dangerous all that toxic smoke is to human health.

Here's William Bringham.

Hey, watch you're back. We're getting flanked again.

It's an apocalyptic scene in Northern California

as the massive park fire outside the city of Chico exploded in size overnight burning 4,000 acres an hour.

I'm gonna end up getting cotton. Firefighters face triple digit temperatures as

neighborhoods went up in flames and gas tanks detonated in the heat.

Yesterday, wildfire cameras caught the formation of a so-called Fire NATO,

a massive vortex of flame and smoke.

The park fire was only 3% contained by this morning,

forcing thousands of people to flee.

We set a prayer over our house,

and we just pray to God.

Paul and Janet Mallory were forced to evacuate but their home was spared.

We're happy that we were out and we we prayed over it and I believe that our house is standing today because of a miracle

There are now more than 60 wildfires burning across Oregon and Washington. The country's largest, Oregon's

Durky Fire, has consumed nearly 300,000 acres and is less than a quarter contained.

There's mom and dad's house.

In Canada, this is what's left of Jasper Alberta.

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