On the evening of 14 January 1858, Napoleon and the Empress escaped an assassination attempt unharmed. A group of conspirators threw three bombs at the royal carriage as it made its way to the opera. Eight members of the escort and bystanders were killed and over one hundred people injured. The culprits were quickly arrested. The leader was an Italian nationalist, Felice Orsini, who was aided by a French surgeon Simon Bernard. They believed that if Napoleon III were killed, a republican revolt would immediately follow in France and the new republican government would help all Italian states win independence from Austria and achieve national unification. Bernard was in London at the time. Since he was a political exile, the Government of the United Kingdom refused to extradite him, but Orsini was tried, convicted and executed on 13 March 1858. The bombing focused the attention of France and particularly of Napoleon III, on the issue of Italian nationalism.