Formula 1 was unable to run first practice at the Eifel Grand Prix because of bad weather.
The Nurburgring was cloaked in fog and damp weather and the medical helicopter was unable to fly.
The nearest suitable hospital is too far away by road for F1 officials to run the session in the context of the risk of an accident and potential driver injury.
The second session is due to start at 14:00 BST but is also under threat.
The lack of running meant Mick Schumacher and Callum Ilott were unable to have their first run in an F1 car on a Grand Prix weekend.
Schumacher, the son of seven-time champion Michael, was due to drive the Alfa Romeo in place of Antonio Giovinazzi, while Briton Ilott was in Romain Grosjean’s Haas.
The pair are members of the Ferrari Driver Academy and both are potential candidates for a seat in F1 next season.
Lewis Hamilton enters the weekend with the chance to equal Schumacher’s all-time record of 91 Grand Prix victories.
He leads Mercedes team-mate Valtteri Bottas by 44 points in the championship with seven races remaining.