'Feuerzauber' (iv) was the German destruction of the bridges, with the exception of the Ponte Vecchio, over the Arno river and other waterways in and near Florence in northern central Italy as Lieutenant General Mark W. Clark’s US 5^th Army approached the city and the Germans fell back from the 'Arno-Linie' defences to those of the 'Gotisch-Linie' (3 August 1943).