Washington's Tunnel 5 Fire burns structures, forces hundreds from homes

A wildfire forced hundreds of people from their homes in southwestern Washington as firefighters battle rugged terrain and hot, windy conditions to stop the blaze from causing further destruction.

The Tunnel 5 Fire broke out July 2 in Skamania County, Washington, around 50 miles northeast of Portland, Oregon, and has since burned through more than 500 acres.

At least 10 structures have been destroyed, according to initial estimates provided to CNN by fire and sheriff's officials, and many more homes are threatened by the flames.

An evacuation order by the Skamania County Sheriff's Office for a 4-mile radius around the fire includes the entire Underwood area and its 1,000 to 1,200 residents, Skamania County Sheriff Summer Scheyer told CNN.

Scheyer said the fire was "too unpredictable" to rescind any evacuations but she is looking for any opportunity to shrink the evacuation zone so people can get back home safely.

"I am doing everything I can to get these levels relaxed, however, I do not want to risk anyone's life by being reckless in trying to push those levels to be relaxed. We're utilizing fire expertise to try and make that decision," Scheyer said.

The entire Pacific Northwest is in the throes of a heat wave with numerous record temperatures expected, including in nearby Portland, Oregon, which is forecast to hit 98 degrees. The hot, dry, windy conditions are making it exceptionally difficult to get the upper hand on the fire, which is now 5% contained. Well above-average temperatures in the low to mid-90s and winds up to 15 mph with even higher gusts will challenge the firefighters through Thursday.

It is also burning in the Columbia River Gorge area, a sprawling canyon up to 4,000 feet deep in places, making it exceptionally difficult to fight, fire officials told CNN.

"It's extremely steep. There are some areas that have cliffs and we cannot put people and boots on the ground in those areas," Heather Appelhof, the public information officer for the Tunnel 5 Fire told CNN.

The cause of the fire is still under investigation. The Washington Department of Natural Resources said on Twitter six small fires were started by fireworks over the weekend in the same region as the Tunnel 5 Fire, but they were put out.

Skamania County officials urged residents to "exercise extreme caution" if using fireworks on the Fourth of July and fireworks celebrations at the Port of Hood River, close to the Tunnel 5 Fire, were canceled.

"This is a community event, and it will not feel the same to celebrate while such a large part of our community is actively undergoing loss. Our thoughts and focus should remain on this wildfire," Hood River Fireworks' lead pyrotechnician said in a statement.