This far exceeds the 13.7 million tweets sent during the Super Bowl in February, typically the largest media event of the year.

Founded in 2006, Twitter has sought to position itself as a "second screen" media product that users can pull up on their smartphones while watching events like the Super Bowl or the Olympics on television.

But the service has shone as a communication channel during major disasters, such as in the wake of the 2011 tsunami in Japan.

Twitter, which has been susceptible to occasional outages, stayed up glitch-free this week, serving at times as a vital source of information for afflicted residents.

The number of times that users in New York City loaded their home timeline from a mobile device peaked around 9 p.m. Monday night, around the time an explosion at a Consolidated Edison transformer knocked out power, more than doubling the total from the previous two days, the company said, without providing details.

The 20 million tweets included the terms "sandy," "hurricane," "#sandy," and "#hurricane," the company said.

(Reporting by Gerry Shih; Editing by Richard Chang)

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