Conversation so far:
what was the premise of world war 1
World War I began in 1914 after the assassination of Archduke Franz Ferdinand and lasted until 1918.
how did the assassination of archduke franz ferdinand lead to world war 1
The assassination of Archduke Ferdinand was the spark that caused Austria-Hungary to strike the first blow and all the European powers quickly fell in line to defend their alliances.

Question: how many people died in the war
Self-contained rewrite: how many people died in world war 1