Berlin Brandenburg Airport (BER) opened in 2020, nine years later than planned, with Terminal 1 coming into service at the end of October, and flights to and from Tegel Airport ending in November. Due to the fall in passenger numbers resulting from the COVID-19 pandemic, plans were announced to temporarily close BER's Terminal 5, the former Schönefeld Airport, beginning in March 2021 for up to one year. The connecting link of U-Bahn line U5 from Alexanderplatz to Hauptbahnhof, along with the new stations Rotes Rathaus and Unter den Linden, opened on 4 December 2020, with the Museumsinsel U-Bahn station expected to open around March 2021, which would complete all new works on the U5. A partial opening by the end of 2020 of the Humboldt Forum museum, housed in the reconstructed Berlin City Palace, which had been announced in June, was postponed until March 2021.