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By David Morgan
NEW YORK, Aug 16 (Reuters) - Life returned to normal on Saturday for millions caught in the worst blackout in North American history, but isolated outages stubbornly continued in communities from Michigan to Connecticut and Ontario, Canada.
Two days after cascading outages cut electricity to 50 million people, a U.S.-Canadian task force prepared to search for the cause while utilities scrambled to get power generation back to capacity before the start of the work week on Monday.
"Until the systems are fully up and operational, until the demands start to return to full peak ... there remains the potential for rolling blackouts," U.S. Energy Secretary Spencer Abraham told reporters after speaking to the governors of New York, New Jersey and Connecticut.
"Our first goal is to just get the existing generation back on line. That's going to take some time," he added.
The three states, where an estimated 30 million people were effected by the blackout, called on Abraham for what New Jersey Gov. Jim McGreevey described as "a thorough, complete, agonizing" investigation into the cause.
"On Monday, millions of New Yorkers are going to set foot back into the subways of New York. We know that our system will be up and running. But we cannot say with 100 percent accuracy that it won't happen again until we know what happened and what steps are being taken to prevent it," said New York Gov. George Pataki.
McGreevey blamed the blackout on a lack of infrastructure investment to replace antiquated equipment that he disparaged as 1950s "Edsel" technology.
The National Electric Reliability Council, a Princeton, New Jersey-based nonprofit company set up after a huge blackout struck the East Coast in 1965, suggested the outage started when three transmission lines failed near Cleveland, Ohio.
In New York City, full power returned late on Friday after 29 hours. Subway trains began running on Saturday, while stores and restaurants opened for what they hoped would be their first normal day since the lights went out on Thursday afternoon.
"Finally it's back to normal. I never thought this would happen here," said Marie Matthew, a Haitian-born Manhattan security guard who was making her way home to New Jersey for the first time since Wednesday.
Public officials urged residents to conserve energy by keeping lights, air-conditioners and washing machines switched off.
"We're still in a delicate balance between what we can generate and the demands on the utility grid," said Pataki, who told reporters that the state's power grid was operating 43 percent below capacity and meeting demand only by taking in energy from out-of-state.
Airport delays continued, while thousands of stranded travelers stood in line at John F. Kennedy, LaGuardia and Newark Liberty airports hoping to book new flights after hundreds of cancellations.
'RELIABILITY' A MISNOMER
In the Midwest, where energy officials believe the blackout began, residents of Cleveland and Detroit boiled their drinking water after the blackout paralyzed water system pumps. But water service returned to all but a few isolated areas.
"Everyone should have water to their house unless there's been some sort of mechanical problem," Cleveland Mayor Jane Campbell told Fox News.
The return of full electricity service to Detroit also raised the prospect that the Big Three automakers would avoid production shortages. The Chrysler arm of DaimlerChrysler AG said the blackout affected 31 of its plants but that the facilities would all be operating by Monday. Only one Chrysler assembly plant in St. Louis operated over the weekend.
But sporadic outages continued in isolated sections of Connecticut and New Jersey, while in Ontario, officials warned of possible rolling blackouts as utility authorities worked to stabilize the region's power grid.
New York officials estimated that the leading U.S. metropolis may have lost $40 million in taxes and paid as much as $10 million in extra overtime during the blackout. The New York Times reported that losses in personal income among 8 million city residents could run as high as $750 million.
State health officials were expected to conduct special food inspections at New York restaurants and stores, while sanitation workers collected tons of garbage laden with rotting food from home refrigerators and freezers.
The outage that plunged the region into darkness eclipsed major blackouts which paralyzed eastern cities in 1965 and in 1977. Both times, stricken communities were assured that a similar crisis would not happen again.
Pataki noted the irony that the National Electric Reliability Council was set up to promote reliable energy after 1965. "If ever there was a misnomer, it's the 'electric reliability council.' We did not have reliability," he said.
On Friday, the White House announced that a cross-border task force would investigate the massive blackout following talks between U.S. President George W. Bush and Canadian Prime Minister Jean Chretien.