Until the very end all possible solutions to save the airline have been tried. The British regional airline was struggling for some time now, aid packages and a bailout deal with the British government have been negotiated. Unfortunately, all the efforts still led to the administration of the airline as publicly stated on their website.
Passengers are advised to not travel to the airport unless they have organized alternative travel options already. The airline will not organize alternative travel. Affected passengers are advised to get in contact with the Civil Aviation Authority, to discuss further possible proceedings. With recent bankruptcies such as with Air Berlin or Germania, the best way to get your money back, was a chargeback through your credit card.
What actually caused the bankruptcy remains unknown. Rumors say that the Coronavirus crisis and the resulting slump in revenue may have caused the airline to file bankruptcy.