By Charles Sheehan and Dan P. Blake

A private construction crew working downtown tore into three underground power lines near Millennium Park, cutting power to 10 downtown buildings Friday, according to Chicago emergency officials.

Commonwealth Edison Co. rerouted power and restored energy to eight office buildings and two residential high-rises, said spokesman Jeff Burdick.

No injuries were reported and there were no reports of people needing assistance getting out of elevators, according to fire officials.

One woman said an elevator at 360 E. Randolph St. stopped, but it powered up almost immediately.

A residential high-rise at 155 Harbor Drive had its power restored about 8 p.m., and the one at 400 E. South Water St. was restored about 9 p.m., Burdick said.Esther C. Lawson said she had just stepped off the elevator in the first floor of the building at 155 Harbor Drive close to noon when everything went black for a moment.

Emergency lighting did come on almost immediately, she said.

Lawson's husband remained on the 37th floor with their 13-month-old granddaughter, she said.

"It's better him than me up there," she said. "He's an ex-policeman and he's got some survival skills."

The Fire Department opened the bulkhead doors on the roof of the building and the air rushing through was keeping temperatures down, said Fire Commissioner Raymond Orozco.

Yet with temperatures hovering around 90 degrees, a number of residents were steaming.

Air-conditioned city buses were parked on the street for residents who needed them, but they remained empty. Most residents that remained near the building sat on benches along the sidewalk and enjoyed strong lake breezes.

Mobile generators had been brought in to support a nearby power substation.

The damage to the power lines near 360 E. South Water St. was extensive and continued to affect traffic signals and bridges, said ComEd spokeswoman Tabrina Davis.

Swissotel Chicago, a few hundred yards away, put up 120 rooms free of charge for residents who felt they needed a place to stay, said Andrew Velasquez, executive director of the Office of Emergency Management and Communication.

"We are in contact with the Department on Aging, the Red Cross, and the Salvation Army," Velasquez said. "We are calling to make sure individuals in these buildings have the resources they need."