DENVER (Reuters) - Investigators probing the cause of a deadly Colorado wildfire that charred more than 300 homes, making it the most destructive in state history, have located the point of ignition but have not concluded how the blaze started, officials said on Thursday.
At its height, the 12-day-old blaze forced the evacuation of some 35,000 people in and around Colorado Springs, the state's second most populous city, and threatened the campus of the U.S. Air Force Academy before fire crews gained an upper hand late last week.
Since it was first reported on June 23, the blaze has burned more than 14,000 acres of drought-parched timber and brush, mostly in the Pike National Forest about 50 miles south of the Denver metropolitan area. But as of Thursday, ground crews had managed to carve containment lines around 90 percent of the fire's perimeter, said incident commander Rich Harvey.
Harvey said he anticipates full containment by late in the week as crews work to extinguish flames in a few stubborn areas.
"When there's been no smoke visible and no heat detected for 24 hours, we'll be comfortable there will be no further growth and we'll call it 100 percent contained," Harvey said.
Investigators, led by U.S. Forest Service experts, have identified the spot where the so-called Waldo Canyon fire began. But Lieutenant Jeff Kramer, spokesman for the El Paso County Sheriff's Office, said he was "not at liberty" to reveal the location because the investigation was continuing.
"The cause has not yet been determined," he added.
The blaze initially gained media attention as it erupted near some of Colorado's best known landmarks, including the famed Pikes Peak mountaintop whose panoramic summit vistas inspired the song "America the Beautiful."
Stoked by strong, erratic winds and record triple-digit air temperatures, the fire turned deadly last Tuesday as it suddenly roared through containment lines into a residential subdivision that rests in the bluffs of the city's western fringe.
The wall of flames reduced 346 houses to ash, marking the biggest single loss of property ever from a Colorado wildfire, and President Barack Obama paid a visit to the Waldo Canyon fire zone last Friday.
The bodies of two people were found in the ruins of one home, raising to six the overall death toll from a state fire season authorities are calling the worst on record.
Most of the residents displaced by the fire have since been allowed to return to their homes.
Meanwhile, Colorado Springs Police Chief Peter Carey said an anonymous donor has offered a $50,000 reward for information leading to the arrest of anyone who looted the homes of evacuees, following dozens of looting reports.
Reporting and writing by Keith Coffman; editing by Steve Gorman, Cynthia Johnston and Todd Eastham