Delay might endanger the outcome of the entire campaign, because it was essential that the main body of Allied troops be engaged before Army Group A established bridgeheads. To overcome this difficulty, the Germans resorted to unconventional means in the Battle of Fort Eben-Emael. In the early hours of 10 May, DFS 230 gliders landed on top of the fort and unloaded assault teams that disabled the main gun cupolas with hollow charges. The bridges over the canal were seized by German paratroopers. The Belgians launched considerable counterattacks which were broken up by the "Luftwaffe". Shocked by a breach in its defences just where they had seemed the strongest, the Belgian Supreme Command withdrew its divisions to the KW-line five days earlier than planned. Similar operations against the bridges in the Netherlands, at Maastricht, failed. All were blown up by the Dutch and only one railway bridge was taken, which held up the German armour on Dutch territory for a short time.