Lufthansa has cancelled about 1350 flights, due to a pilot strike. The strike is hitting medium and short haul flights today (Monday, 12/1) and long-haul flights on Tuesday. About 150,000 passengers are affected.
The main strike issue is Lufthansa’s attempt to cancel early retirement plans presently enjoyed by pilots. DETAILS
Believe these pilots strikes have been a recurring (if minor — unless your flight is canceled) problem for Lufthansa.