A stubborn fire in two electrical transformers at the Kennedy Center for the Performing Arts and an apparently related short circuit in an underground power cable at Wisconsin Avenue and K Street NW caused scattered power failures throughout the Foggy Bottom and Georgetown areas last night and left some homes and businesses without electricity for seven hours or more, authorities reported.

The cause of the problem, which left the Kennedy Center without air conditioning as performances went on as scheduled, had not been determined early today.

Authorities said the fire at the center, which began shortly after 5 p.m. in an underground power-control vault, kept rekindling and took about four hours to extinguish.

Potomac Electric Power Co. crews and D.C. firefighters were dispatched at about the same time to Wisconsin and K, where nearby residents had reported the sound of an explosion below ground and smoke pouring from a manhole.

Pepco officials said no injuries were reported in either incident, which resulted in outages throughout the area, particularly along Virginia and New Hampshire avenues and 23rd, 24th and K streets NW.

An undetermined number of residences and 23 large commercial buildings were affected, including the Kennedy Center and portions of the Watergate complex, Pepco said.

"We don't have any hot water and we don't have any air conditioning," said an official at the Watergate Hotel.