All flights to Frankfurt are being redirected due to a significant computer issue at Lufthansa.

Germany’s air traffic control announced on Wednesday that all flights are being rerouted from Frankfurt, the nation’s busiest airport, due to a major disruption caused by Lufthansa’s computer troubles.

According to agency spokesperson Robert Ertler, every available parking spot for planes in Frankfurt is occupied because passengers and crew are unable to board their flights.

“All arriving aircraft are being sent to alternative locations,” including Munich, Nuremberg, and Düsseldorf, Ertler informed the Associated Press.

The Lufthansa Group, which encompasses subsidiaries like Swiss International Air Lines and Eurowings, stated that the IT failure was linked to construction activities in the Frankfurt area.

“This is leading to flight delays and cancellations,” the company stated. “We apologize for the inconvenience faced by our passengers.”

Deutsche Telekom later reported that an excavator accidentally severed fiber optic cables buried 16 feet deep while working on a railway project.

The company indicated that some sections of the damaged line have already been fixed, and conditions are expected to improve significantly by Wednesday afternoon, according to the German news agency dpa.

As per dpa, all of Lufthansa’s domestic flights have been canceled, and travelers are encouraged to consider alternative travel options, such as trains.