Ljubljana Jože Pučnik Airport has lost almost half of its route network after its dominant carrier, Adria Airways, canceled all scheduled flights and initiated bankruptcy proceedings on Monday. Slovenia’s de facto national carrier said it filed a motion for bankruptcy proceedings because of the company’s insolvency and the relevant national legislation that “obligates the management of a company in the position of Adria Airways to file for bankruptcy proceedings of the company.” The court has three days to decide on the opening of bankruptcy proceedings, it noted.

Adria’s demise marks the fourth airline bankruptcy in Europe in September, after Thomas Cook Airlines UK and Aigle Azurt and XL Airways in France.

The Slovenian regional carrier’s widely expected failure follows a temporary grounding of part of its scheduled flights earlier this month and the repossession of two of its Bombardier CRJ900s by Trident Aviation Leasing Service. Slovenia’s CAA removed the aircraft, carrying registration S5-AAU and S5-AAV, from Adria’s AOC and the Slovenia aircraft registry, the agency confirmed September 19. The airline’s fragile financial footing first surfaced last year when the country’s CAA launched several procedures to assess whether the carrier fulfilled all the requirements for the operating license of an EU airline. The body cleared Adria in January, but soon afterward the airline again made headline news due to a dispute with Sukhoi Civil Aircraft Company over the terms of the long-term lease of 15 SuperJet 100s.

The Slovenian government sold its national airline in 2016 to Luxembourg-based private equity fund 4K Invest.

According to Adria’s website, it operated three Airbus A319s, nine CRJ900s, two CRJ700s, and six Saab 2000 turboprops on some 20 scheduled routes from its main base at Ljubljana, Slovenia’s capital and main gateway, and secondary bases in Pristina, Kosovo, and Tirana, Albania.

Adria Airways flew as a member of the Star Alliance since December 2004 and operated under codeshare agreements with several of the grouping’s members, including Air Canada, Lot Polish Airlines, SAS, Turkish Airlines, Singapore Airlines, Lufthansa, Austrian Airlines, Swiss, and Brussels Airlines. It operated AMCI flights for Lufthansa, Austrian, and Swiss.

Swiss said about 10,000 passengers felt the effects of Adria Airways’ bankruptcy—Adria operated Lugano-Zürich-Lugano on behalf of Swiss—and added it had turned its focus to “an equivalent connection with the train.”

Ljubljana Airport is losing connectivity to several capitals. Owned by Fraport, the airport called Adria Airways “an important and valuable business partner from the opening of the airport in 1963 onwards,” and added it “deeply regrets” the airline ceased operations. Adria Airways operated flights to 16 destinations from Ljubljana: Amsterdam, Brussels, Vienna, Frankfurt, Copenhagen, Manchester, Munich, Paris, Podgorica, Prague, Priština, Sarajevo, Skopje, Sofia, Tirana, and Zurich.

Brussels Airlines announced on Tuesday that it will will start operating flights between Brussels Airport and Ljubljana on November 4 to fill the gap left by Adria. It will serve the route six times weekly with an Airbus A319.