パリ砲
In the spring of 1918, the German army launched a new offensive and threatened Paris once more, bombing it with the Paris Gun. On 29 March 1918, one shell struck the Church of Saint-Gervais and killed 88 persons. Sirens were installed to warn the population of impending bombardments. On 29 June 1917, American soldiers arrived in France to reinforce the French and British armies. The Germans were pushed back once again, and the armistice was declared on 11 November 1918. Hundreds of thousands of Parisians filled the Champs Élysées on 17 November to celebrate the return of Alsace and Lorraine to France. Equally huge crowds welcomed President Woodrow Wilson to the Hôtel de Ville on 16 December. Huge crowds of Parisians also lined the Champs Élysées on 14 July 1919 for a victory parade by the Allied armies.