Updated: 4:46 p.m.

House staffers were sitting in the dark Tuesday afternoon after the power in the Longworth House Office Building suddenly shut off at about 3:30 p.m.

Architect of the Capitol spokeswoman Eva Malecki said emergency generators restored some lighting initially and the power was back up shortly afterward. Pepco, she said, had been performing upgrades to their equipment, inadvertently cutting the electricity to Longworth.