After a fiber-optic malfunction shut down Alaska Airlines’ ticketing ability for four hours, by late on Monday the company was running on a close to normal schedule. The airline and its regional carrier were forced to cancel 78 flights causing delays and inconvenience for about 7,000 customers.

Despite the disruption over 130 other flights left, some delayed as much as four hours by the failure.

“Flights are running real close to schedule right now in all major cities. We expect tomorrow to be back on track completely,” said airline spokeswoman Marianne Lindsey on Monday evening.

All the trouble began at 8am on Monday morning when the computers used by the airline to check-in their passengers crashed. Employees were forced to board passengers by hand, often sticking handwritten flight numbers onto computer screens. The source of the malfunction was two severed fiber-optic lines in Sprint’s network.

The worst-affected cities were Alaska Airline’s hubs of Seattle, Portland, Los Angeles, Anchorage and San Francisco.