The Granite Mountain Hot Shots survived the initial explosion that caused the Yarnell Hill Fire to expand so rapidly.
A source with direct knowledge of what took place on the mountain on Sunday described what happened between 4:45 p.m., when the fire erupted, and 5:55 p.m., when the National Fire Administration estimated the firefighters deployed their fire shelters.
The source said the firefighters retreated into a previously burned area, known as "the black" to wildland firefighters.
At that point, the Granite Mountain Superintendent, Eric Marsh, spoke into his two-way radio and said, "We're in the black. We're good."
For a reason unknown to the source, the Granite Mountain crew left the area where they originally fled and tried to make it to a nearby ranch.
Fire investigators say the ranch was the crew's designated safety zone. But they never made it. The fire overtook the team in a basin, about a quarter of a mile from the ranch.
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