SAN DIEGO (CBS) — A federal probe into a massive power outage last year has revealed major coordination problems among electrical grid operators that went beyond any single-source failure.

KNX 1070’s Tom Reopelle reports the findings shed some light on a blackout that left 2.7 million customers in Southern California, Arizona and Baja California without electricity.

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Regulators with the Federal Energy Regulatory Commission (FERC) and North American Electric Reliability Corp. (NERC) blamed a lack of planning and operating in an unsecured state for the outages last September.

“Several transmission operators did not know that over 600 megawatts of generation in a key location was out for maintenance, and did not reflect this in their planning studies,” said Heather Polzin of the FERC office of enforcement.

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Utility officials previously said an employee’s work on a transmission line in Arizona started the chain of events, but that conclusion was undermined by the new report, which denied that event alone could trigger such a massive blackout.

Operators may have avoided cascading blakouts with more effective analysis of real-time information that may have allowed them to reduce their energy load or dispatch additional generation to prevent a more widespread outage, regulators said.

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