Blackout probe points to failure in Cleveland area

THE probe into what triggered a blackout that left 50 million people in the dark zeroed in on an area just south of Cleveland in the US state of Ohio.

With power finally restored, meanwhile, life was returning to normal in cities across the region yesterday, though there were lingering reminders: garbage cans overflowing with spoiled food, continuing water-boil warnings and the flood of questions asking how could it happen.

Michehl Gent, head of the North American Electric Reliability Council, suggested human error might have been the reason the problems were not isolated before they knocked out power from Michigan to Ontario to New York.

“The system has been designed and rules have been created to prevent this escalation and cascading. It should have stopped,” Mr Gent said in a telephone conference call.

Mr Gent said investigators were examining more than 10,000 pages of data, including automatically generated logs on power flows over transmission lines, to determine what caused the blackout.

FirstEnergy Corp, the Akron, Ohio-based utility that officials said owned at least two of the three lines, said alarm systems that might have alerted engineers to the failed lines were broken, but that functioning backup systems had been in place.

Nearly all of the millions affected by the blackout had power restored by Saturday, but people were still being urged to conserve electricity and many remained harried by aftereffects.

Thunderstorms Saturday knocked out power to a few thousand customers in the Detroit and Lansing areas.