SEATAC, Wash. - Hundreds of flights at Seattle-Tacoma International Airport were canceled Friday morning and throughout the day due to icy conditions on the runways.
According to FlightAware, Sea-Tac had nearly 500 cancelations.
At about 5 a.m., airport officials said it had to close its runways indefinitely to de-ice the surfaces.
"Safety is our priority before we can reopen the runways," officials tweeted.
Seattle-based Alaska Airlines had to cancel all of its Alaska and Horizon flights in and out of Seattle and Portland before noon.
Crews continued to clear the runway after 9 a.m.
The airport is advising travelers to check with their airline for updates on their specific flights.