Meanwhile, the column under Seras encountered opposition on the 15th when it reached the Predil Pass blockhouse. While Eugène crushed Gyulai's command on 17 May, Seras bombarded the Predil fort without effect. Engineer Captain Johann Hermann von Hermannsdorf commanded the garrison of two companies of the 1st battalion of the Szluiner Grenz Infantry Regiment Nr. 3. In order to bring his artillery, cavalry, and wagon trains to Tarvis, Eugène needed to use Predil Pass. He sent three battalions south to attack Hermann's bastion from the pass while Seras drove in from the other side. The French assault began on 18 May and met with tremendous resistance. Hermann and every single one of the 250 Croat defenders were killed in their last stand. Out of 8,500 infantry and 12 guns, Franco-Italian losses were about 450 killed and wounded.