Hard to believe.
"Heavy snowfall overnight on Friday had far-reaching consequences for hundreds of travelers at Munich Airport. As was announced today, they were forced to spend the night in planes on the tarmac. Their flights scheduled for Thursday evening had been canceled.
Around 500 passengers were already on board and the planes were ready for takeoff, according to a Lufthansa spokesperson after the incident. However, due to the snow, they were not given permission to take off, the spokesperson added.
It was no longer possible to return to the terminal: “At that point, all parking spaces for aircraft directly at the terminal were already occupied and bus capacity on the aprons was limited,” the airport said. ...
Passengers and crew remained on board the aircraft until morning. According to Lufthansa, three Lufthansa flights to Singapore, Copenhagen, and Gdansk were affected, as well as two Air Dolomiti flights to Graz and Venice. ..."
Source: article by BR (public German broadcaster for Bavaria)
Translated with DeepL.com (free version)