Thousands of travelers flying to and from the East Coast were delayed Tuesday by an earthquake that shook airport terminals and forced the evacuation of air traffic control towers at some of the nation's busiest airports.
Immediately after the quake, the FAA ordered planes at airports around the country to stay on the ground rather than fly to airports in New York, Philadelphia, New Jersey, Washington, D.C., and Virginia where traffic was temporarily halted. Among major airports in the region, only New York's LaGuardia continued operations throughout the day.
By late afternoon, traffic at all the airports was returning to normal, although delays were expected into the evening.
Delta Air Lines said it expected to cancel about 15 flights from JFK and a dozen flights from Reagan National because of the earthquake. JetBlue had resumed all operations, but it was urging passengers to check their flight status and expect delays both in and out of East Coast airports. JetBlue reported seven diversions, but no cancellations.
American Airlines diverted four planes away from the earthquake zone, said spokesman Tim Smith.
"In those first minutes, we didn't know what we had, so we sent them elsewhere until we had a better handle on what the conditions were," Smith said. He said all four planes would be refueled and eventually continue to their scheduled destination, although delays could snowball in the busy New York air corridor.
"Airplanes are coming and going," Smith said, "but at the New York airports, when you get a delay it tends to stay."
United Airlines diverted two JFK-bound planes; one to Pittsburgh and the other to Hartford, Conn. Both were expected to finish the trip to New York later Tuesday, said airline spokeswoman Megan McCarthy.
"We do have some delays, but (the earthquake) was a fairly minimal impact," she said.
Southwest Airlines expected delays on the East Coast to continue into Tuesday evening but didn't expect widespread cancellations, said spokeswoman Beth Harbin.
Two hours after the earthquake, the FAA was still reporting delays at Newark Liberty International Airport and Reagan National Airport near Washington. Flights leaving the Philadelphia airport also experienced delays of more than an hour Tuesday afternoon.
There were transportation snarls elsewhere along the East Coast as well. Amtrak reported train service along the Northeast Corridor between Baltimore and Washington, D.C., was operating at reduced speeds. Amtrak crews were inspecting stations and railroad infrastructure before returning to normal operation.
Washington's Union Station _ which serves Amtrak, commuter trains and the Metro subway _ was evacuated due to falling plaster. Metro officials said subway trains were undamaged, but were operating at reduced speeds.
The towers at Kennedy, Newark and Reagan National airports were evacuated during the quake, according to officials for the FAA and the National Air Traffic Contollers Association.
Tim Hardison, an official with controllers association, said Andrews Air Force Base in Maryland was closed to air traffic. Air traffic for the base is handled by controllers working for FAA.
Laura Brown, a spokeswoman for the Federal Aviation Administration, who was evacuated from FAA's headquarters in downtown Washington, said in an email that she wasn't aware of equipment outages.
But Hardison said the FAA regional air traffic control center in Leesburg, Va., was "shaking pretty hard" during the quake, which was centered in Virginia.
"Everyone was aware that something not-so-good was going on. I can't describe how long it lasted because we were all just looking at each other," Hardison said in an email.
"We are still trying to talk to aircraft because they wanted to know why they were shaking," he said in an email about an hour after the earthquake. "No one was in a panic state, but people were trying to figure out what was going on."
Controllers at the center, which handles air traffic for several airports in Virginia and Maryland, "just kept doing their job," he said.
After the quake, all controllers in the building _ including those taking their breaks _ were ordered back to the control room "to make sure everything was squared away there," Hardison said.
AP airline writers David Koenig in Dallas and Samantha Bomkamp in New York contributed to this report.