Updated 3:50 p.m. - Let there be power!
NStar reported on its Twitter feed just before 3:30 p.m. that electricity has been restored to all customers in Boston except the Prudential tower.
The nearly 4,000 homes and businesses who had lost power since Tuesday night's transformer fire were without electricity for about 45 hours.
The Prudential tower was still expected to regain power later today.
Updated 1:45 a.m. - It's back!
The infamous Citgo sign in Kenmore Square is back on, according to Twitter users who snapped photos of the iconic sign tonight.
NStar is also confirming that electricity is coming back on for most Back Bay customers.
At about midnight NStar reported that it had returned power to 8,500 more customers. About 4,000 remain without power.
Those without power overnight were expected to get it back by 6 a.m., according to city officials.
While 4,000 homes and businesses are still without power, that number is down from about 20,000 on Tuesday night when the fire broke out in the Back Bay transformer.
Updated 8:30 p.m. - It might be a little longer than originally anticipated to get your power back if you live in the Back Bay.
While city officials tweeted earlier this afternoon that power in the Back Bay/Kenmore area would be on by 7 p.m., many customers in that neighborhood are still in the dark, including the iconic Citgo sign.
The Prudential and Copley Square area was expected to get power back about 4 a.m., but that remains to be seen.
City officials more recently reported that NStar officials said there was a delay in switching on the power.
"NStar expects remaining customers to have power restored by later this evening or early Thursday morning. Some customers may experience intermittent outages over the next few days as we continue to work on the system," according to the power company.
As the 7 p.m. hour passed, residents were left wondering when they would see the light again.
"7pm has come and gone...still no power in the Kenmore Fenway areas? Can we have an update?," tweeted @ficodiaz7
Updated 9:45 a.m. - Power that's been out in the Back Bay since early yesterday night will likely be restored by this afternoon or this evening.
City and NStar officials held a news conference this morning to update people on the working being done to restore power in the Back Bay after a three-alarm fire broke out last night in a substation housing a 115,000-volt transformer.
About 11,000 customers still remain without power in the Back Bay area.
"We expect to have half on today by 2 p.m. and the remainder on this evening," said Joe Nolan, a senior vice president with NStar.
Originally 20,000 customers were without power, but officials were able to reactive a section of the city after the fire was put out. Power was restored to that section about 3 a.m.
Residents with concerns or questions can call the mayor's hotline at 617-635-4500.
Metro's original story is below:
Thousands of power customers in and around the Back Bay are without electricity tonight and could be for at least the remainder of the night and in to tomorrow morning.
City and NStar officials said tonight that they expect some power to be back on as early as 1 a.m. and more homes and businesses to have power by tomorrow morning.
However, officials were quick to add that power would not be restored for everyone tomorrow.
Officials also warned for commuters to plan ahead for tomorrow morning's commute.
"Power outages in Dalton St. area may continue until am, impacting biz, transit & am commute. Plan accordingly," the city wrote on its Twitter alert feed.
The Prudential and Symphony stations on the Green Line remained closed as of 11:15 p.m., but the other nearby stations including Hynes, Arlington and Massachusetts Avenue were reopened.
The Massachusetts Avenue bridge was also closed to inbound traffic coming in to Boston, as was the Prudential Center I-90 tunnel.
It was unclear when the T stations and roadways would reopen.
The three-alarm fire broke out about 6:30 p.m. in a garage on Scotia Street that houses a pair of transformers. At least one of the 115,000-volt transformers caught fire and caused officials to shut down power to the neighborhood.
With much of the Back Bay darkened, police have set up at intersections and other locations around the neighborhood to ensure safety.
The Back Bay Hilton hotel was evacuated because it was adjacent to the hotel. While residents were told about 11:15 p.m. that they could return to their homes, the hotel was still trying to find places to put up its guests.