It happened late Sunday afternoon near the town of Yarnell in west-central Arizona- about 70 miles northwest of Phoenix.
Those killed were Prescott's "Granite Mountain Hot Shot" firefighter crew- reportedly overrun by a wall of flames when the wind shifted.
A 20th firefighter from the crew managed to escape- although injured to an unknown extent.
Some had deployed their emergency heat tents while some had not- according to current media reports.
In the town of Yarnell- population around 650- one TV news report stated "the entire town was destroyed" by the fire.
The nearby town of Peeples Valley- population around 430- remained threatened as the fire was "zero percent contained" per a live TV interview with a fire official at 1 am Monday morning Kansas City (Central) time.
There were reported to be civilian injuries- less than a dozen per various media sources- fortunately none reported critical.
Temperatures were at or approached 120-degrees Sunday afternoon and the heat blew up isolated thunderstorms which probably contributed to the fire's sudden wind shift.