Firefighters have gained ground against the sprawling blaze in central Arizona that killed 19 members of an elite 'hotshots' crew in the worst loss of life in a US wildfire in 80 years.
While the fire remained dangerous and unpredictable, it was no longer burning out of control, and fire managers expected to report some measure of containment by day's end, officials for the fire command team said.
''We gained some ground... it's been a pretty good day, and the fire has stayed mostly parked where it was 24 hours ago,'' said Jim Whittington, a spokesman for the incident commander.
Another command spokesman, Dennis Godfrey, said separately that the so-called Yarnell Hills fire, burning through dense, dry brush about 130km northwest of Phoenix, was posing no immediate additional threat to property in the area.
Whittington said the 500 firefighters battling the blaze got a break on Monday night and Tuesday (local time) from powerful, erratic winds that earlier had stoked the fire and caused volatile changes in its direction.
But he said fire managers were concerned about thunderstorms that appeared to be moving into the area late on Tuesday (NZT Wednesday), bringing the possibility of a renewed burst of strong, unruly winds.
The blaze, ignited at the weekend by lightning, has blackened at least 3400 hectares of thick, tinder-dry chaparral, oak scrub and grasslands as it burned largely unchecked for four days.
Authorities say 50 to 200 structures, most of them homes, have been destroyed in and around the tiny town of Yarnell, but they said more time would be needed to deduce a firmer figure on property losses.
Yarnell and the adjacent community of Peeples Valley, which together are home to roughly 1000 people, remained evacuated.
Fire incident commander Clay Templin told displaced residents at a community meeting today that despite ''good progress'' made against the fire, evacuees would probably not be allowed to return to their homes before the weekend.
On Sunday (NZT Monday), a specially trained squad of 19 firefighters known as ''hotshots'' died in the fire after they were outflanked and engulfed by wind-whipped flames in a matter of seconds. They did not have time to scramble into their cocoon-like personal shelters.
The tragedy marks the highest death toll among firefighters or civilians from a US wildland blaze since at least 25 men died battling the Griffith Park fire of 1933 in Los Angeles, according to the National Interagency Fire Center, based in Idaho.
The fallen Arizona firefighters were based in the town of Prescott, about 50km northeast of the fire zone, and residents there paid tribute to the 19 men, most of them in their 20s, in a memorial service on Tuesday evening (NZT Wednesday).
A 20th member of the team, who was acting as the crew's lookout at the time of the disaster and survived unscathed, is ''very distraught'' and has declined to speak to the media, according to Prescott Fire Department spokesman Wade Ward.
A makeshift shrine has sprung up outside a downtown Prescott fire house, drawing dozens of people who paid their respects by leaving flowers, flags, condolence cards, photos and mementos at the site.