PRESCOTT, Ariz. (AP) - PRESCOTT, Ariz. (AP) - Higher humidity overnight helped make conditions at a deadly Arizona fire a bit less volatile.
But fire spokeswoman Karen Takai says the Yarnell Hill Fire is still zero percent contained, and thunderstorms that bring little rain and a lot of lightning are a major threat because of the dry vegetation.
She says winds are calm Tuesday morning but thunderstorm cells were already visible.
At last count, about 500 firefighters are on the scene, with more on the way.
The Yarnell fire has burned about 8,400 acres, or about 13 square miles.
It killed 19 firefighters Sunday when they were overtaken by the flames.
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Investigators from several agencies are expected to go to the scene of a wildfire that killed 19 elite firefighters.
A Southwest fire official says the crew and its commanders were following safety protocols, and it appears that the fire's erratic nature simply overwhelmed them.
The fire in the town of Yarnell is zero percent contained and has burned some 8,400 acres.