Crimson flames and thick smoke have engulfed entire mountains.

Residents in the western U.S. state of Nevada were ordered to evacuate on Sunday, local time, due to a massive wildfire that broke out in the north.

As of Sunday night, the wildfire had burned more than 11,000 acres.

[Michael Weaver / Resident: Nobody wants to sit outside for hours in murderous heat that's over 100 degrees Fahrenheit.]

The fire is spreading along the border with California, a state that is also suffering heavily from wildfires.

Highways were temporarily closed, causing severe traffic congestion.

Strong winds also triggered a fire tornado phenomenon, whipping the flames upward.

[Darin Balaam / Sheriff: A sudden gust of wind can cause the flames to flare up again. That is precisely why we are restricting residents from entering the area.]

In Utah, located east of Nevada, casualties occurred during firefighting operations.

A helicopter deployed for firefighting operations crashed, resulting in the deaths of both the pilot and an occupant.

In the case of the wildfire that broke out in Washington state last week, evacuation levels have been downgraded, but firefighting operations are not yet complete and the extent of the damage remains massive.

Wildfires also continue across the border in Canada.

A wildfire in British Columbia forced about 12,000 residents to evacuate.

Large-scale wildfires show no sign of stopping as strong winds and hot, dry weather persist.

(Video by Park Eun-ha)