A wildfire that has already charred 15,000 acres of land in California now threatens the water and power supplies for San Francisco.
The "Rim Fire" was within 2 miles of the Hetch Hetchy Reservoir, which supplies most of San Francisco with its water.
California officials already declared a state of emergency last week over the threat the fire posed to San Francisco's power infrastructure.
Scott Cohn reports from the scene of the fire.
—NBC News contributed to this report.