The wildfire in Colorado Springs has been declared the worst in the state's history, devouring 346 homes and leaving at least one person dead, with most of the fire still burning out of control.
The cause of the fire is unclear but officials will investigate to determine whether arson played a role, El Paso County Undersheriff Paula Presley told ABC News in an exclusive interview.
"It's really important that they [firefighters] get to the point of origin before we can ever get to that determination," Presley said.
"Anytime we have a fire of undetermined origin, we're going to treat it as arson. ... To ensure that it is thoroughly investigated and we get to the point of origin and make sure that either rule out arson, or determine that it is arson," Presley said.
More than 85 percent of the fire is not contained, officials said, so the investigation will continue after the fire is under control.
"This in many ways is a type of terrorism where somebody is trying to destroy an entire city, essentially," Presley said. "I'm a native here. I've never seen anything like this."
Police Chief Pete Carey said late Thursday the remains of one person were found in a home where two people had been reported missing. He didn't elaborate or take questions after making the announcement.
From the ground, the Colorado community is a wall of flames. More than 20,000 homes are still threatened by the unrelenting fire. Aerial photos best tell the story of the mass devastation, which did little to ease the concerns of anxious residents waiting to find out the fate of their homes.
Tempers flared as property owners fought with officials to check on their homes to see if anything was salvageable.
"You don't have the authority to tell me I can't go back into my house," one angry homeowner said. "I looked this up. I'm not flying off the cuff here. I have rights as a property owner."
Evacuees were called to a meeting at the University of Colorado campus. Anne Marie Borrego of the Red Cross said a list was passed around with the homes that were damaged or destroyed.
"It was a really tough meeting," Borrego said. "I have to say just sitting there, I kept thinking to myself how difficult it must be to wait for that list to actually be handed out to look for your own address and see if it was on it."
Police continue to guard evacuated areas after two arrests were made for looting.
President Obama declared a major disaster late Thursday, making federal funding available in Colorado Springs' El Paso County as well as Larimer County, where a fire that erupted two weeks ago killed a woman and destroyed 257 homes.
Obama was to tour fire-stricken areas today as hundreds of locals and some tourists who were staying at Red Cross shelters hoped life would return to normal. Others stayed with friends and family.
There is reason for optimism as temperatures are expected to reach into the mid-80s, about five degrees cooler than Wednesday and Thursday.
The Associated Press contributed to this report.