Crews worked into the night to restore power to sections of the city a day after a smoky electrical transformer fire in the Back Bay area.
Electrical utility NStar said Wednesday it expected it would be overnight before power would be restored to all its customers. By 11 p.m. Wednesday, power had been restored to 8,500 customers. At the peak of the outage, 21,000 customers were without lights.
NStar said it had installed temporary cables and dozens of generators to bring back power until permanent repairs can be made, but the extensive work was taking longer than first expected.
There were still traffic restrictions, but no problems were reported. The Massachusetts Turnpike's Exit 22 ramps to Copley Square and Prudential Center were closed to allow for the electrical work.
All subway stations in the area reopened Wednesday afternoon.
Many businesses and the Boston Public Library remained closed. People showed up for work Wednesday and were told to go home. Schools in the area were up and running.
Police will maintain a visible presence in the area until things are back to normal, police Commissioner Edward Davis said.
There were no reports of looting or other problems, he said.
"It's a real testament to the people of the city," he said. "... Even the driving has been respectful."
The city sent inspectors to restaurants in the affected area to make sure no spoiled food was being served, Mayor Thomas Menino said. Many were using dry ice and refrigerated trucks.
The fire plunged a huge swath of the city, from the Back Bay to Chinatown and Kenmore Square, into darkness on Tuesday night. Skyscrapers, normally lit up even when no workers are inside, stood eerily dark. Hotels, bars and some homes were evacuated.
There had been some concern that the heavy black smoke that billowed across the city the first minutes of the fire was toxic, but authorities later said it was not.
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.