( CNN ) -- Severed telecommunications cables disrupted ticketing and airport check-in systems at Alaska Airlines on Monday , creating long delays and cancellations for thousands of passengers traveling at the end of a busy holiday weekend . The Seattle-based airline said in a statement that it had to manually process passengers at key hubs after its Sprint network , which services ticketing , reservations and check-in , went down at 7:30 a.m. Pacific time . Service came back up around noon . Seventy mainline and regional flights affecting some 6,000 passengers were canceled . Delays , in some cases , reached four hours as the outage impacted operations at Seattle , Portland , Los Angeles and Anchorage . Alaska said it expected a handful of additional cancellations and residual delays as it worked to restore normal operations . The airline apologized to passengers , blaming the problem on a `` network outage . '' Sprint spokeswoman Crystal Davis said communication cables were cut nearly simultaneously about 2,000 miles apart , knocking out service to some customers in the Pacific Northwest . The lines were severed near a railroad track between Chicago and Milwaukee and at a location between Tacoma , Washington , and Portland , Oregon . Alaska said it would place delayed passengers on later flights or arrange travel on other carriers . Passengers traveling on Monday and Tuesday were allowed to change their tickets in advance without paying a change fee . However , they were responsible for making up any difference in fares . Low-cost Alaska is the 10th largest U.S. airline , according to Transportation Department data . 'Epidemic level ' of laser attacks directed at planes . Spilled soda blamed for loose jet seats . How would you save American Airlines ?
Severed telecommunications lines disrupted Internet service in Northwest . The outages were caused by a power outage at the company's main fiber optic cable that connects its data centers to customers around the world. Seventy flights canceled , some 6,000 passengers affected ; More delays likely .