New York City Mayor Michael Bloomberg told a press conference that a power failure in northern New York or southern Canada “cascaded through the system” and affected electricity grids as far west as Ohio.
Bloomberg also said that power was coming back on in areas to the north and west of the city and that he expected most electricity service to be restored within hours.
“With a lot of luck maybe the power will be back before dark,” he said.
The mayor reconfirmed his earlier statement to CNN that smoke from a Consolidated Edison Inc. power plant in the city was due to the plant’s automatic shutdown, not to a fire, as had been reported.
New York Gov. George Pataki declared a state of emergency and his spokeswoman said that the suspected cause of the blackout was “a possible transmission problem from Canada to the U.S.,” the Associated Press reported.
A New York State official told CNN earlier that Niagara Mohawk, a power grid that provides electric service to over one million customers in upstate New York, was overloaded and led to a cascading effect on other power centers.
The Federal Energy Regulatory Commission (FERC) told Reuters that the blackout was apparently not caused by any foul play.
“We have no indication that there is any terrorism involved,” FERC spokesman Bryan Lee said.
Bloomberg also told CNN: “I can tell you 100 percent sure that there is no evidence as of this moment whatsoever of any terrorism.”
In New York, as in several other cities, almost all public utilities were affected including the subway system, elevators and airports.
“Right now the power outage is affecting all of our operations. We have no buses, no trains, no subways running. The airports have their perimeters secured and I can’t say right now if flights are coming in or out,” a spokesman for New York’s Port Authority told news agencies.
Reports of blackouts stretched from metropolitan New York to parts of Pennsylvania, Ohio and Michigan as well as Toronto and Ottawa in Canada.
In Toronto, the blackout also ground the public transit system to halt, stranding thousands of commuters trying to get home.
“There’s no power but they’re safe,” a transit official told Reuters of people stuck in the city’s subway stations.
The U.S. Federal Aviation Administration said control centers and airport towers in New York and other cities were running on diesel generators. The outage caused several major airports to shut down and flights to be diverted.
Similar sweeping power outages have occurred in past decades. An overloaded grid in Ontario caused a massive northeast blackout in 1965, which affected Toronto, Boston and New York among others.
A blackout in New York City in 1977 left some 9 million people without electricity for up to 25 hours.
A large power outage swept through several states in the West in 1996 when a circuit breaker failed on a large megawatt transmission line linking Oregon and California.