Investigators focused on an electrical transmission loop Friday that encircles Lake Erie (search) as they tried to understand a massive power blackout that cut across the Northeast and Midwest, leaving millions of people without electricity.
The White House announced a U.S.-Canadian task force will investigate the cause of the blackout and identify actions to prevent it from happening again. It will be headed by Energy Secretary Spencer Abraham (search) and Canadian Natural Resources Minister Herb Dhaliwal.
President Bush said the power breakdown showed "we need to modernize the electricity grid." But, he acknowledged, "Something like this isn't going to happen overnight."
The cause of the blackout, which continued for a second day in many parts of the region, remained elusive as officials first suggested it had been triggered by a malfunction in Ohio and then backed off that assessment as premature. Earlier it had been believed the problem started in Canada, while still another theory had the cause pinned down to eastern Michigan.
No one was sure.
What did become clear, however, was that power grid experts were stunned at the broad reach of the blackout and the speed — a matter of seconds — in which it spread thousands of miles across New York and southern New England to the eastern sections of Michigan and into Canada.
"We never anticipated we could have a cascading outage" of this magnitude and speed, said Michehl Gent, chief of the North American Electric Reliability Council (search), the industry-sponsored organization charged with assessing the dependability of the nation's electric grids.
Precautions were supposed to have been put in place to prevent such a widespread domino effect, he said, vowing to ferret out what triggered the chain of events and to take corrective action.
If the problem began in Ohio or Michigan, as was being speculated, it should never have reached Manhattan, complained New York Gov. George Pataki (search), adding that the grid was supposed to be designed to isolate such problems. "That just did not happen," he said.
But it may be days, even weeks, before solid answers emerge.
As power slowly began to be restored Friday, officials jumped from one theory to another in search for a cause.
Gent at a news conference acknowledged that the answer was somewhere on what is called the "Lake Erie Loop (search)" — a massive, but troublesome transmission loop that encircles Lake Erie from New York to Detroit, into Canada and back to New York.
"That's the center of the focus. This has been problem for years and there have been all sorts of plans to make it more reliable," said Gent.
About the time power was disrupted at 4:11 p.m. EDT Thursday, technicians noticed a stunning development on the northern leg of the loop: some 300 megawatts of electricity moving east abruptly reversed course and within seconds 500 megawatts of power suddenly were moving west.
Electricity flows on its easiest path so it is believed the change in direction was caused by a sudden reduction in power somewhere on the line at the western end of the loop, investigators suggested.
"This was a big swing back and forth," said Gent, adding that throughout the grid system, power levels began to fluctuate. That caused generators and other systems to trip across the region to protect equipment.
More than 100 power plants, including 22 nuclear reactors in the United States and in Canada, shut down, most of them automatically to protect themselves against power surges, officials said.
The whole process "essentially took 9 seconds," said Gent "It happened very quickly."
But what triggered the shift of electricity flow and where?
As of late Friday no one was confident enough to say.
"Speculation is running rampant," said Gent. "I really don't want to speculate."
He said it could be next week before any firm answers are known, but he ticked off a string of factors that authorities are certain played no role.
Reports of lightning hitting a facility in the Niagara Falls (search) area have been ruled out, as have reports that a fire at a New York City electric facility may have triggered the power disaster.
The weather also has been given a reprieve because it was not hot enough either in the Ohio Valley or in the Northeast to cause such a demand on electricity that the system should have overloaded, said Gent. In fact, he said, there was plenty of extra capacity.
And terrorism has been ruled out by everyone from grid managers to President Bush.
But Gent said he wouldn't rule out that negligence by someone, somewhere might have been a cause. Investigators will have to determine whether some industry transmission standards might have been ignored, or perhaps simply conclude that the industry-crafted standards are inadequate.
The political fallout from this week's blackout will be heard long after power is restored. And much of the discussion will center around the need to modernize and, possibly expand, the nation's aging electrical transmission system.
Congressional committees already are staking out time for hearings on the blackout when lawmakers return from their summer recess after Labor Day. Federal and a number of state regulatory agencies also plan to pursue investigations.
Pat Wood, chairman of the Federal Energy Regulatory Commission (search), cautioned not to jump to conclusions until "we see what really happened here." But he said a critical question is to determine why protective safeguards did not isolate the grid failure wherever it occurred.
Rep. Billy Tauzin, R-La., said his House Energy and Commerce Committee plans hearings next month on the causes behind the blackout. He said he anticipated the blackout will spur lawmakers to take a closer look at how to improve the power systems when they work out a final energy bill.
Nora Brownell, another FERC commissioner, said the industry's move toward competition should not be blamed, as some critics of electricity market deregulation have argued.
"It's very clear this is not about deregulation. It's about investing in the transmission system," said Brownell.