“The July 1934 Putsch and Dollfuss's assassination could have been prevented. Since 29 May of that year clear evidence of the planned Nazi conspiracy was available to the Austrian authorities. It came from a number of highly reliable sources. The warnings were passed to the senior security officials who were charged with the protection of the state, the government and the Chancellor. Without doubt some of them collaborated with the Nazi conspirators. Also without doubt some of the others acted with typical Austrian Schlamperei. They did not take the warnings seriously.”
Book:Last Waltz in Vienna