When Szilveszter Matuska blew up a portion of the Biatorbágy bridge near Budapest on 13 September 1931, causing the engine and nine of the eleven coaches of the Vienna Express to plunge into a ravine 30 meters deep, Gyula Károlyi issued two orders imposing martial law. He made use of this tragedy to imprison Communists and to ban all political rallies and processions. Imre Sallai and Sándor Fürst, leaders of the Communist movement, were arrested and executed in 1932 after a show trial. These emergency measures did not improve the situation: there had been no real threat of a mass movement.