9/11 was an attack in one of the most iconic USA cities on civilians, by foreign citizens. The Sarajevo incident was a targeted assassination on the heir of the empire, done in an occupied province, by Austrian citizens of Serbian nationality - it's a risk you get when you have a multinational empire which has a heavy boot on the occupied nationalities in "Europe 's Powder Keg".

The only parallel is that both are terrorist attacks, but you can list some of the "striking parallels" if you want, I would like to see them ...