UPDATE: Riverside County Power Back On

9/9 7 a.m. UPDATE: Power was back on today in areas of eastern and southwestern Riverside County that went dark because of a historic blackout that left up to 6 million people without electricity from Mexico to southern Orange County.

Tens of thousands of Imperial Irrigation District and Southern California Edison customers in Riverside County lost power about 3:30 p.m. Thursday. The irrigation district reported that power was restored to 99 percent of its 150,000 customers by 9:30 p.m.

During the outage, more than 60 patients were evacuated from Desert Springs Health Care nursing home in Indio, when a backup generator failed.

Riverside County firefighters and other emergency personnel moved the patients to other facilities in the area.

The unprecedented outage originated near Yuma, Ariz., and affected homes and businesses in San Diego, Orange, and Imperial counties, parts of Arizona and Baja California. ( to read more about the massive outage in San Diego.)

It shut down the two reactors at the San Onofre nuclear power plant but the facility did not lose power or experience safety issues, according to its operator.

The California Independent System Operator, which manages the state's power grid, blamed the outage on the failure of a high-voltage power line between Arizona and Southern California, saying it affected all SDG&E customers and the customers of other utilities as well.

"The outage was triggered after a 500-kilovolt (kV) high-voltage line
from Arizona to California tripped out of service. The transmission outage cut the flow of imported power into the most southern portion of California, resulting in widespread outages in the region,'' according to Cal ISO.

The Arizona power company APS said the outage appears to have been related to a procedure an employee was carrying out in the North Gila substation northeast of Yuma.

Operating and protection protocols typically would have isolated the resulting outage to the Yuma area. The reason that did not occur in this case will be the focal point of an investigation now under way.

The Indio Police Department lost power for about 40 minutes and used
backup generators, police spokesman Ben Guitron said. The Riverside County Sheriff's Department temporarily handled 911 calls, and Indio police officers were sent to monitor major traffic intersections.

Other cities in the affected area contract with the sheriff's department for police services, so they handled their own 911 calls, La Quinta-based sheriff's Lt. Jason Huskey said. He said officers set up traffic signs at major intersections in the city for traffic control when power went out. --City News Service

9/8 9 p.m. UPDATE: A massive power outage that is affecting San Diego and Orange counties has also struck parts of Riverside County, according to Cal Fire/Riverside County Fire Department spokeswoman Cheri Patterson.

The eastern portion of Riverside County from Washington Street east, including the communities of Palm Desert, La Quinta, Coachella, Indio, Mecca, and North Shore, are blacked out, Patterson reported at 8:24 p.m.

Power is expected to be restored in the county's desert region during the night.

"Imperial Irrigation, the local power company, has notified the fire department that it expects full power returned by 2 a.m. September 9th," Patterson reported.

As power begins coming back, officials are recommending that customers conserve energy to help prevent overload.

In the meantime, officials are busy with emergency calls. An evacuation at Desert Springs Health Care took place tonight after the facility's back-up generator failed.

"A total of 66 patients will be relocated to cooperating facilities," Patterson reported. "One patient has been transported via ambulance to JFK with a heat related injuries."

The county's emergency 2-1-1 system is available for additional questions.

For more updates on the situation in San Diego and Orange counties, --Toni McAllister

9/8 ORIGINAL POST: A massive power outage that is affecting San Diego and Orange counties has also struck parts of Riverside County, according to Cal Fire/Riverside County Fire Department spokeswoman Cheri Patterson.

“We believe they are all related,” Patterson said of the Southern California outages that are impacting nearly 1.4 million customers from the Tijuana border up through south Orange County and into the Riverside County desert regions. “Basically, (the Riverside County outage) is affecting areas east of Palm Desert.”

( to get updates on the outage and to read about what triggered it.)

The Riverside County outage has left nearly 150,000 customers in Indio, Bermuda Dunes, La Quinta, Sun City-Palm Desert and Thousand Palms without power, City News Service reports.

Patterson said triple-digit temperatures in the desert region are of the utmost concern right now. All hospitals in the area are running on backup power, she said, but officials are checking health care facilities in the area that may be without power.

The situation has caused county public safety officials and the Riverside County Office of Emergency Services to “plan for the worst,” Patterson said.

The county’s 211 system may be put online shortly, Patterson said. The system allows residents to call in for emergency updates.

( to get updates on the outage.) --Toni McAllister