The Arizona wildfire that claimed the lives of 19 firefighters is 8 percent contained, fire officials reported late Tuesday.

That report was the first clear sign of progress against the fire in the town of Yarnell. It was reported out of control with no containment since it started last Friday, including a a huge expansion on Sunday when the firefighters were killed.

Crews totaling nearly 600 are on the lines of the Yarnell Hill Fire, which has burned 8,400 acres in grassland and chaparral south of Prescott.

Authorities reported Wednesday that 129 homes and other structures were destroyed in the fire, a revision downward of earlier estimates thart as many as 200 structures had been destroyed.

Members of the Granite Mountain Hotshot crew, made up of firefighters from the city of Prescott, were moving in to work the fire Sunday afternoon when a sudden wind shift trapped them. They deployed heat shields, but the flames overtook them, leaving 19 dead. A 20th crew member survived because he was separated from the others to move a vehicle.

Authorities said Florida's state forester will lead the investigation into the deaths. Jim Karels was named as the lead investigator Wednesday.

Karels was appointed Florida state forester in 2008. He served four fire seasons with the U.S. Forest Service and is the committee chairman of the National Association of State Foresters Wildfire.

Mike Dudley, acting director of cooperative forestry of the U.S. Forest Service, will be the secondary team lead.

Authorities said they hope to let people return to their homes by the weekend, and contain the fire within the next two weeks.