A failure in the nation's electrical grid cuts off electricity to New York and other Northeastern cities, hitting airports, cell phone networks and companies such as IBM.
The outage also affected the electric supply in neighboring New Jersey, as well as in Toronto and Ottawa, on Thursday afternoon. Other areas--such as Cleveland and Toledo in Ohio, and Detroit--suffered a blackout as well.
News outlets initially reported that the outage was the result of a failure in the Niagara Mohawk power grid. As of Friday morning, U.S. and Canadian authorities were still trying to determine exactly how the problem started.
In New York, the Nasdaq market and the New York Stock Exchange opened on time Friday.
Worries that the outage had been caused by terrorists were quickly dismissed. In a televised press conference Thursday, New York Mayor Michael Bloomberg said there is "no evidence of any terrorism whatsoever."
Internet performance tracker Keynote Systems said the outage had not slowed the Internet.
"At this time (1:50 pm PDT Thursday), the Internet is performing normally and major Web sites in the U.S. are also performing normally, although a few of the news Web sites are showing slightly longer download times," Keynote spokesman Dan Berkowitz wrote in an e-mail.
Technology companies in New York such as IBM were affected.
"The power is out here at our New York-based facilities as it is everywhere," said Brian Doyle, a spokesman for IBM, speaking from the company's headquarters in Armonk, N.Y. "We have lights and computer connectivity powered by generators. But other than that, we are in the same boat as everyone else."
America Online, the largest U.S. Internet service provider, witnessed a dip in simultaneous users around 1 p.m. PDT, according to spokesman Nicholas Graham. The count fell from 2.4 million members online to 2.1 million.
Graham, who is based in Dulles, Va., could not say whether parent company AOL Time Warner had evacuated its offices. Calls to New York-based representatives were not answered.
The outage was sending high call volumes through both cellular and landline telephone networks late Thursday. Sprint spokesman Dan Wilinsky said that all the company's PCS and long-distance switching centers in the affected areas are running via backup power, but that the added volume is causing congestion on its networks.
Also, some individual cell towers might not be working, but Wilinsky said the company did not have an estimate of how many sites might be affected. In addition, Wilinsky said Sprint may block some calls to the East Coast at some point to ensure that emergency calls from the area get through.
"Customers are being asked not to call unless it is absolutely necessary," Wilinsky said.
Verizon Wireless also said its network was also up, though some of its cell sites and switches were running emergency generators. Like Sprint, the company said it was experiencing extremely high demand. It advised customers who are having trouble getting through to wait several minutes before redialing their call.
The outage brought a halt to all flights departing from both major airports serving New York City, as well as flights departing from Newark, N.J., Cleveland, Ottawa and Toronto, according to the Federal Aviation Administration. Northwest Airlines flights out of Detroit were also grounded, an FAA representative said.
Most flights meant to arrive at those airports were also being delayed, except flights from the West Coast, according to another FAA representative. Planes were permitted to take off from West Coast cities because power was expected to have been restored by the time those flights were ready to land on the East Coast.
The Air Traffic Control System Command Center is fully operational, according to the FAA, and the travel halt was the result of an inability to power the security equipment used to screen passengers. The aviation agency said major delays were expected throughout the United States.
Companies outside the blackout area said they were working to assist customers affected by the outage. Greg Eden, a spokesman for storage giant EMC, said in the case of an outage, the company's gear typically has enough power to take all data stored in memory and write it to disk before powering down.
"Our customer service organization is fully engaged in the situation and in contact with affected customers," Eden said.