<span>The assassination of Archduke Franz Ferdinand</span> lead to a direct conflict between the two powers (Austria and Russia) and further lead to the war. Hope that helps.
It was a trigger that was competing two powers in Europe. Russia and Qustria-Hungary.Franz was killed by a separatist and the Austrians wanted to see the separatist punished for what he done, while on the other hand. Russia supported him.
