Drivers in the Old Town Alexandria area faced some traffic delays Thursday morning when a power outage caused traffic lights in the area to stop working.

At 5:52 a.m., power went out for about 1,850 households and businesses in the area, according to Dominion Power. Officials there said only seven customers remained without power by 8:30 a.m. and traffic lights were functioning by then.

Chuck Penn, a spokesman for Dominion said it was not clear what had caused the power to go out but officials believed the problem occurred underground.

The customers still affected are expected to have power back by 10 a.m., he said.