Arizona wildfire: Investigators’ answers will be in the details

PRESCOTT, Ariz. — Investigators who arrived here from around the country are trying to close in on what led to the deaths 19 elite firefighters, sifting through weather records, radio conversations and ground conditions as they piece together just how the men were overtaken by the wildfire.

Key to determining the firefighters’ final frantic moments when they became trapped by the Yarnell Hill fire will be autopsy reports, including blood analysis that will suggest just how quickly the men perished.

On Thursday, authorities who reviewed the reports would only say that the men died from “fire-related” reasons.

WHO THEY WERE: Fallen Arizona firefighters

Yet investigators are undoubtedly looking at carbon monoxide levels in the blood, which can let them know if the firefighters died from breathing in superheated air, said Dick Mangan, a retired fire investigator who has assisted two dozen similar probes nationwide.

“I’ve had to talk to a lot of parents of dead firefighters,” the 68-year-old Mangan, a retired U.S. Forest Service investigator, told the Los Angeles Times. “Using this information, one thing I’ve been able to tell them is ‘Your child didn’t suffer.’ ”

On Thursday, officials said the Yarnell Hill fire was 45% contained, but warned that there were still dry conditions and hot pockets. Wind remained a significant factor.

More than 600 people were still working within the fire zone, including a team of eight to 10 fire experts who arrived Wednesday, beginning what officials described as a 60-day process they hope will explain what happened to the Granite Mountain crew as they tried to protect homes in the subdivision of Glen Ilah, near the town of Yarnell.

PHOTOS: Yarnell Hill fire

Mangan, a 46-year firefighting veteran who investigated two previous fires in Arizona and Colorado that took the lives of 20 firefighters, said the Granite Mountain crew was trying to create what is known as a survival zone.

“They were in a situation where they had to make some very rapid decisions and take rapid action,” he said. “It’s a pretty desperate move. You’re supposed to have these safety zones identified ahead of time. But things change in a fire and these guys are trained to be adaptable.”

He said protocol for safety zones is to contain a radius that is four times bigger than the height of the flame. “That means the closest person to a fire with 20-foot flames should be 80 feet from the fire to keep from being burned by the radiant heat. They obviously could not do that.”

Mangan talked about the complex job that now lies ahead for incident investigators.

The Yarnell Hill fire, he said, shared many similarities with Arizona’s 2009 Dude fire, which killed six firefighters, and Colorado’s 1994 Storm King Mountain fire, in which 14 firefighters died. All featured a sudden weather change that created a wall of flames that firefighters were unable to escape.

In such scenarios, the sudden change of wind speed and direction, Mangan said, can cause chaos on the fire lines.

“Guys might think they were working the flank of the fire but if a thunderstorm cell passes or a towering smoke column collapses, the winds can go completely haywire,” he said. “Things change in a heartbeat. You get fire moving in all directions. If you thought you had a good escape route, chances are it has been compromised.”

He said temperatures on the day of the Dude fire reached 122 degrees. “The temperatures the Granite Mountain hotshots were facing were over 100 degrees. The heat and fuel conditions were very similar. They were both dangerous fire days.”

In previous investigations, Mangan said, officials have tried to determine the trapped firefighters’ “situational awareness.”

“We try determine: Did they know which way was out and which way would have gotten them into more trouble? In hilly terrain, the fire often obscures the horizon and the smoke is often heavy enough that they can’t see the sky.

“That’s why these firefighter teams have a lookout. In the Yarnell Hill fire, the lookout was forced from his position by the fire. The lookout said, ‘It’s hot and heavy and I’m out of here.’ The message to the crew was that they better do something, too.”

Firefighters are trained to deploy their heat shields in 30 seconds or less. Prescott fire officials suggested Thursday that the Granite Mountain hotshots were trapped by the fire but could not clear brush in time to create a sufficient safety zone.

Many were found huddled in the space there was. Mangan said they followed training protocol.

“We teach people that if they group their shelters together, it allows them to communicate, and give each other confidence that they can survive this. The intent is to reflect the radiant heat, and grouping together also helps that.”

Mangan said that the fact that some Granite Mountain hotshots were found outside their fire shields means that they they either did not have time to deploy them or that they abandoned their shields because of the heat.

“Sometimes they leave the shields too early,” he said. “Or they felt is was so hot inside they couldn’t stand it anymore. In the Dude fire, one firefighter yelled out, ‘I can’t take it anymore,’ and left. He walked 15 feet before he died from the radiant heat.”

Mangan said the investigative team meets twice a day, morning and evening.

“We look at everything — what we can throw out, what is no longer important. You need to establish the facts. You can talk to five or six people who will say that black is black and the other will say black is white. Who’s right?”

Firefighters, he said, are trained to do whatever it takes to save lives — their own, and those of their crew members.

“Because your mission is to get home at night. Everything grows again — grass, trees, houses. The only thing that doesn’t grow again is the firefighters.”

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john.glionna@latimes.com