From the old news archive of our newspaper:
November 16, 1937: The Grand Duke and Duchess of Hess were among 11 people killed when a Sabena Junkers JU-52 airplane crashed near Ostende, Belgium.
The plane was piloted by Tony Lambotte, one of the most senior in Sabena service, with over six hundred thousand flying miles to his credit. In his crew were an engineer, a wireless operator and a mechanic. Among those on board were the Hereditary Grand Duke Georg Donatus of Hesse (b. 1906), his wife, former Princess Cecilie of Greece and Denmark (b. 1911) who was heavily pregnant at the time, their sons Ludwig (b. 1931) and Alexander (b. 1933), the Grand Duke's widowed mother, former Princess Eleonore of Solms-Hohensolms-Lich (b. 1871), Baron Joachim von Riedesel, and Lina Henar, the children's nurse. The group were travelling to London for the wedding of the Hereditary Grand Duke's younger brother Louis. Baron von Riedsel was to be Louis' best man.
The head of the family, Grand Duke Ernst Ludwig (who had tried to end World War I by a desperate mission into Russia to confer with the Czar in 1916) had died on Oct. 9, causing the postponing of Prince Ludwig's marriage to Margaret Campbell Geddes in London for seven weeks. Grand Duke George, the new head of the family, his wife Princess Cecilia of Greece and Denmark, two sons and the Dowager Duchess, as well as the newly born son of Princess Cecilia, were all killed. The child's unexpected arrival apparently caused the tragedy, as the pilot tried to land at Ostend, an unscheduled stop. Prince Ludwig, social attache at the German Embassy in London, went ahead with the wedding on the following day; his best man was his cousin Prince Louis Mountbatten.
About the curse of the House of Hesse:
...The Hesse-Kassel constitution was symbolic--symbolic, in 1831, of the aspirations of many German liberals; symbolic, in later years, of their frustration. Once the revolutionary fervor had subsided, the elector's government made a determined effort to whittle down the powers of the legislature. Its point man in this enterprise was Ludwig Hassenpflug (1794-1862), minister of justice (1832-34) and of the interior (1832-37). Though married to the sister of Jacob and Wilhelm Grimm, Hassenpflug did not share the political outlook of his brothers-in-law. Instead, his name quickly became a byword for reaction, lending itself to the alliterative word play "Hassenpflug--Hesse's curse" (Hassenpflug--Hessens Fluch). In fact, one of Hassenpflug;s first targets was the principal architect of the 1831 constitution, the Marburg law professor Sylvester Jordan. The legislature fought back by bringing suit against Hassenpflug in the land's highest court--the first impeachment proceedings in German constitutional history. Hassenpflug left the government in 1837. Though the tug-of-war between legislature and various ministries took on a quieter tone over the next decade, Hesse-Kassel, when the 1848 revolution broke out in Paris, very much had the appearance of a state stranded in constitutional limbo..."
So in first way, it had nothing to do with the hemophiliac disease etc. The synonyme is based on this.