There were no immediate reports of serious injuries, but streets in and around the area were shut down, and hotels, bars and some homes were evacuated. Subway trains were not stopping at stations in the area. Massachusetts Turnpike exits leading to the area were closed.
Fire officials said large plumes of dark, heavy smoke at the height of the fire weren’t toxic, though police asked people to stay away from the area so they did not inhale it. One person was taken to a hospital with minor breathing problems.
The fire, in a 115,000-volt transformer, was first reported at about 6:30 p.m. near a garage behind the Back Bay Hilton Hotel. That hotel and the nearby Sheraton were evacuated as a precaution. The fire greatly diminished after the power was shut off.
Vera Leader, who works in King’s bowling alley across from the fire, said employees watched from the roof as the smoke got worse and worse until the power finally went out.
“We could see from the top of the roof that there was a lot of smoke billowing over,” she said.
Mike Duran, a spokesman for the utility NStar, said a problem in one electrical substation spread to a second one. He said the power outage was affecting Back Bay, Chinatown, the theater district, Kenmore Square and parts of the South End. He said about 20,000 customers were affected. He said once the damage is assessed the company will begin working to restore power with large generators.
Officials said it could be Wednesday before power is fully restored.
“The only way you can really put out an electrical fire is you have to shut the power off,” fire department spokesman Steve MacDonald said.
The city used portable floodlights to illuminate key intersections, amid a heavy police presence. Traffic was snarled on Storrow Drive, a major east-west throughfare along the Charles River.
On the city’s fashionable Newbury Street, stores were shuttered and the only illumination came from emergency lights in buildings, vehicle headlights and the glow of cell phones. A few people carried glowsticks.
The landmark Citgo sign at Kenmore Square near Fenway Park went dark.
Historic Copley Square was plunged into darkness except for emergency lights, including in the high-rise landmark Hancock building. At the ornate Boston Public Library, closed because of the outage, stacks of books could be seen through the windows of the mostly darkened building.
