PATAGONIA, Ariz. --
A wildfire burning in southern Arizona grew overnight.
The Duke Fire has now burned about 3,500 acres, according to officials in the Sierra Vista Ranger District of the Coronado National Forest.
The fire is burning about 12 miles south of Patagonia.
Firefighters said the high winds make Monday a key day in their efforts to keep the flames from spreading.
The fire is about 5 percent contained, according to forest worker estimates. That is down from 30 percent Sunday night, when the fire had only burned about 500 acres.
Investigators said the fire is human-caused, but they haven't determined exactly how.
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