Flights were temporarily halted Monday night at Philadelphia International Airport because of a power outage affecting the air-traffic-control tower, officials said.
At 7:23 p.m., airport officials reported on Twitter that a ground stop was in place "due to equipment outage at the FAA tower."
People complained that flights were stuck on runways or being rerouted because of the equipment problem in Philadelphia.
At 7:40, airport officials tweeted that the power was back on, but the ground stop was still in place.
The ground stop was lifted at 8:48, with some arriving flights running nearly two hours behind schedule.