Washington (CNN) -- Power was restored Thursday to two terminals at Ronald Reagan Washington National Airport near downtown Washington a little more than two hours after a fire caused an outage, a spokesman said.
Despite the power cut, air traffic control operations continued to operate on supplemental power, said Rob Yingling, spokesman for the Metropolitan Washington Airports Authority. Some security checkpoints temporarily shut down but resumed operations within an hour on auxiliary power, Yingling said.
The power cut was due to a fire at an airport substation just before midday, he said, adding that the power was restored shortly after 2 p.m.
No one was hurt in the fire, and officials were still trying to determine what caused it, Yingling said.
The power outage affected ticket counters in Terminals B and C for Delta Air Lines, United Airlines, American Airlines and U.S. Airways, Yingling said. Long lines formed at ticket counters in the affected terminalsThursday afternoon.
Passengers should download boarding passes before they come to the airport and go directly to security checkpoints, advised Tara Hamilton, another airport spokeswoman. She warned that baggage handling also was affected, with some airlines trying to check luggage without computers.
CNN's Mike M. Ahlers and Larry Lazo contributed to this report.