Updated at 4:39 p.m. ET: Alaska Airlines has fixed the computer problem that delayed flights Monday across its 64-airport network on the West Coast and in Mexico and Canada, and operations slowly were returning to normal.
The problem was caused by a severed fiber optic line that cut the Seattle-based airline's connection to its ticketing system at 7:40 a.m. PT.
Lines of frustrated passengers grew at the airline's hub in Seattle-Tacoma International Airport and at other airports as the company was unable to put passengers on planes, except by handwritten paperwork.
Alaska Airlines said the data connection was restored before 1 p.m. but passengers could still expect some delays as the system adjusted.
The problem was caused by a combination of two fiber optic cuts in the Sprint system. One occurred at a construction site along railroad tracks between Chicago and Milwaukee and the other was somewhere between Portland and Seattle, said Sprint spokeswoman Crystal Davis in Reston, Va.
"Typically if there's just one cut traffic reroutes automatically," Davis said. "Because there were two cuts with hours of each other, it caused this disruption."
The airline told waiting passengers at Sea-Tac they could rebook later at no charge.
About half the flights at Sea-Tac are Alaska Airlines or its sister airline, Horizon Air.
No other airlines or any airplanes at Sea-Tac were affected by the problem, airport spokesman Perry Cooper said. But lines were out the door in the Alaska Airlines part of the terminal.
Seattle-based Alaska Airlines is the seventh-largest U.S. airline based on passenger traffic and is the dominant U.S. West Coast air carrier. It has an average of 436 flights a day at 64 destinations.
Alaska and Horizon Air are owned by Alaska Air Group.
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