Facebook Inc. and Twitter Inc. became conduits of information for people seeking help or solace as superstorm Sandy ravaged the mid-Atlantic and Northeast states, reinforcing social media's importance in connecting people during a crisis.
At least one observer also named it an Instagram event.
On Facebook's Talk Meter, which measures conversations on specific subjects, Sandy was the second-most popular U.S. topic for 2012, with only the Super Bowl driving more activity, according to the owner of the world's largest social network.
Some of the most-shared terms on Facebook were "we are OK," "power" and "damage," the company said.
Facebook, which has more than 1 billion users worldwide, and Twitter, with more than 140 million, usually see increased traffic around storms and major news events, including Hurricane Irene in 2011, the presidential debates and the London Olympics.
The rise of social media is giving users more information and points of view than television news, where Americans have typically turned during such events, said Charlene Li, an analyst at Altimeter Group in San Mateo, Calif.
"It's not only the immediacy, but also the depth and the breadth that social media is actually impacting," Li said. "It is endless amounts of content. You just can't get through it. It's constantly refreshed."
Utilities and government officials turned to Twitter, a microblogging service that lets users post 140-character messages, to give updates as the storm progressed. Tweeters included New York Gov. Andrew Cuomo, New York City Mayor Michael Bloomberg, New Jersey Gov. Chris Christie and power company Consolidated Edison Inc.
Twitter itself published a blog post listing storm-related resources, accounts and hashtags to follow for real-time information, and suggestions for using the site during an emergency.
This time the rush has moved beyond traditional social media, Li said.
Instagram, a photo-sharing service that Facebook acquired earlier this year, has become a popular way to post images from the storm in the New York area, she said.
The service, which lets friends easily share photos taken from mobile phones, has more than 100 million users, the company said earlier this month.
"This is very much an Instagram news event," Li said. "Up to this point, Instagram has been about taking a picture and putting some sort of special effects around it. That's not what this is."
The storm left 8.11 million electricity customers without power in 17 states and the District of Columbia, from South Carolina to Maine and as far west as Michigan and Indiana, according to the U.S. Department of Energy, including 62 percent without power in New Jersey, and 31 percent in Connecticut.