Colorado Springs under threat as 32,000 flee Waldo fire
More than 32,000 people have fled Colorado's second-biggest city because of raging wildfires that have hit six other US states.
Traffic and smoke choked the streets as people left Colorado Springs and a nearby US Air Force Academy.
Evacuation orders were issued for much of the city as the fire doubled in size to over 24 sq miles (62 sq km). Some 800 firefighters have been deployed.
President Barack Obama is to tour the affected areas on Friday.
Just weeks into the annual wildfire season, there are also fires in Montana, Wyoming, New Mexico, Arizona, California and Utah.
In Utah, a body was found in the ashes of a fast-moving wildfire to the south of Salt Lake City.'Epic firestorm'
At a press briefing on Wednesday morning, officials in Colorado said fire crews had worked through the night. But the blaze was only 5% contained.
End Quote Hillory Davis Colorado Springs resident
As we were driving, the ash was falling out of the sky”
Weather conditions were not favourable.
Dry, hot temperatures are expected to continue across much of the US this week, with little chance of rain.
"We do expect all of our lines to be challenged today," incident commander Richard Harvey said, adding that erratic winds could make their job harder.
One Colorado Springs hospital said it had treated about 20 patients in the last 24 hours for respiratory-related illnesses, a local newspaper reported.
The Waldo Canyon Fire, which began on Saturday, has been fanned towards Colorado Springs by winds of up to 65mph (104km/h).
"It was like looking at the worst movie set you could imagine," Colorado Governor John Hickenlooper said after surveying the fire from the air on Tuesday.
"It's almost surreal. You look at that, and it's like nothing I've seen before."
Heavy ash and smoke was billowing from the hillsides west of Colorado Springs and southbound traffic was temporarily closed on Interstate 25, which runs through the city.
Fleeing residents covered their faces with T-shirts to breathe through the smoke.
"It took us an hour to drive a mile because of the traffic. It was really tense. As we were driving, the ash was falling out of the sky. We couldn't see the street because of the smoke," Colorado Springs resident Hillory Davis, 22, told the BBC.
Meanwhile, Richard Brown, the Colorado Springs fire chief, described the blaze as a "firestorm of epic proportions".
The city of 419,000 people is Colorado's second largest, situated just off the main north-south highway.
It is home to the sprawling campus of the US Air Force Academy, the top school for cadets joining the Air Force.
On Wednesday afternoon, academy officials said the fire had spread to about 10 acres of the campus. Some 2,100 people were evacuated from base housing overnight.
Firefighters from the Air Force and local crews were trying to stop the blaze reaching the academy.
Elsewhere in Colorado, the High Park fire in the west of the state has been burning for weeks and remains barely half contained, although fewer homes are under imminent threat.