The power failure, the largest in North American history, cut a huge swath across the northeastern United States and Canada, paralyzing New York City, Detroit, Cleveland, Ottawa and Toronto, among other areas.
The New York State Independent System Operator, or NYISO, which operates the New York power grid, said power had been restored to more than half of New York City’s 19 million residents.
Many New Yorkers spent the night sleeping outside, many unable to return home amid the outage. Airlines cancelled approximately 400 flights, warning that disruptions could worsen.
Downtown Detroit remained largely shut down Friday, and officials said it could take days to return full service to the city, as well as much of Michigan. Governor Jennifer Granholm declared a state of emergency in the state Friday.
In Canada, Ontario officials said they expect it will take “well into the weekend” to restore sufficient power.
“The province as a whole will have about half enough generation today,” Hydro Ottawa chief executive Ron Stewart told Reuters Friday.
Authorities continued to investigate the cause of the blackout, but dismissed a fast-spreading computer virus or terrorist act as the reason for the widespread outage. Officials are also trying to determine why the power outage sparked a chain reaction that resulted in further losses.
Michael Gent, president of the North American Electric Reliability Council (NERC), which monitors power grids to ensure reliability, said at a news conference that the root cause may not be known until next week, with more in-depth investigations lasting several months.
“We never anticipated we would have a cascading outage,” he said, noting that more than 100 power plants — including 22 nuclear reactors — were shut down.
Although the investigation continues, some have said the massive blackouts points to the vulnerability of the aging electrical infrastructure.
“We’re a superpower with a Third World grid. We need a new grid,” New Mexico Governor Bill Richardson, secretary of Energy during the Clinton administration, said.
President Bush, speaking from California Friday, called the event a “wake-up call.”
“The grid needs to be modernized, the delivery systems need to be modernized. We’ve got an antiquated system.”
Procedures implemented following a huge outage in 1965 were supposed to limit power outages to a confined area; these stopgaps failed Thursday, causing a chain reaction power loss as station after station became overwhelmed and shut down to prevent damage to equipment.
The House Energy and Commerce Committee launched an investigation into the cause Friday. According to Chairman Billy Tauzin (R-La.), the full committee will conduct a hearing in September, when Congress returns from vacation. In a written statement, Tauzin said the power outages illustrate the need for a national energy strategy.
“The only sure way to prevent this nightmare from occurring time and time again, in cities all across America, is to modernize and improve our outdated energy policies,” Tauzin said.
Tauzin said New York City Mayor Michael Bloomberg, New York Governor George Pataki, Energy Secretary Spencer Abraham and Federal Energy Regulatory Commission Chairman Pat Wood would be among those invited to testify before the committee.