Authorities have ordered nearly 200,000 people in northern California to evacuate an area below a dam spillway that may collapse. A failure of the spillway at Lake Oroville Dam could unleash a massive flood.
An emergency spillway at the Lake Oroville Dam has threatened to fail and unleash an wave of flooding on downriver communities.
The National Weather Service said the dam itself remained intact and only the auxillary structure was in danger of collapsing.
A state of emergency has been declared in three counties in northern California and nearly 200,000 people ordered to evacuate.
Officials were forced to use the emergency spillway at Lake Oroville Dam after rainfall in January and February caused water to rise to maximum levels.