 Complete the following phrase:  In June 1914, Bosnian Serb student Gavrilo Princip assassinates Archduke Franz Ferdid in Sarajevo, setting off a chain of events that lead to the outbreak of World War I. Austria-Hungary declares war on Serbia, and the local authorities begin to incite Višegrads non-Serb population against the towns Serb residents. The bridge with the old road to Sarajevo suddenly regains its importance, as the railway line is not adequate to transport all the materiel and soldiers who are preparing to attack Serbia in the autumn of 1914. Austria-Hungarys invasion is 