Update at 7 p.m.: "Power has been restored in Cambridge," the city's police department just tweeted.
Earlier, the MBTA tweeted that "normal service is resuming" on the Red Line.
Earlier updated post:
A widespread power outage has been reported in the eastern part of Cambridge.
As of 6:15 p.m Thursday, NStar said about 13,000 customers are affected, down from a high of 17,000 customers. The area includes Kendall Square near MIT and Harvard Square.
An NStar spokesman said the outage, which occurred just after 4:30 p.m., is related to a transmission line and is being investigated. Cambridge Police said it will take several hours to fix.
Cambridge Police were directing rush-hour traffic. There were reports of gridlock on Memorial Drive and other roads in the city.
The MBTA said "the Red Line is experiencing significant delays between Park Street and Alewife Stations due to [the] power problem." MBTA spokesman Joe Pesaturo said none are stuck in tunnels.
WBUR's Fred Thys was at Harvard at about 5 p.m.:
I just walked through the Harvard campus and much of it was out, many of the residential halls were out. Although parts of Harvard Square, the businesses, seem to have light. Traffic lights, along Memorial Drive, some of them at least, are out right now.
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With reporting by The Associated Press and the WBUR Newsroom
This article was originally published on November 29, 2012.
This program aired on November 29, 2012. The audio for this program is not available.