A group-wide IT system failure at Lufthansa stranded thousands of passengers on Wednesday. The German airline blamed the complications on underground engineering works at a railway station in Frankfurt cutting several fiber optic cables.

According to Lufthansa, repairs would take until Wednesday afternoon, citing information it had received from Deutsche Telekom. It expects flight operations to stabilize by early evening.

⚠️Important information on flight disruption: As of this morning the airlines of the Lufthansa Group are affected by an IT outage, caused by construction work in the Frankfurt region. Unfortunately, this has led to flight delays and cancellations. We are working on –

— Lufthansa (@lufthansa) February 15, 2023

Photos and videos from several German airports showed thousands of passengers waiting to be checked in.

Passengers took to social media to describe how the failure affected the workflow in the terminals, with boarding being conducted via pen and paper.

Lufthansa suffering a global (!) IT outage, resulting in no digital processing of passenger luggage. Aircraft take off without processed luggage. Elsewhere passenger records are done via pen and paper. https://t.co/hA0A400FXY

— Alex Luck (@AlexLuck9) February 15, 2023

More than 200 flights were canceled at Frankfurt Airport due to an IT failure at Lufthansa on Wednesday but landings have resumed, airport operator Fraport said.