Omaha, the most heavily defended sector, was assigned to the U.S. 1st Infantry Division, supplemented by troops from the U.S. 29th Infantry Division. They faced the 352nd Infantry Division, rather than the expected single regiment. Strong currents forced many landing craft east of their intended position or delayed them. Casualties were heavier than all the other landings combined, as the men were subjected to fire from the cliffs above. Problems clearing the beach of obstructions led to the beachmaster calling a halt to further landings of vehicles at 08:30. A group of destroyers arrived around this time to offer supporting artillery fire. Exit from Omaha was possible only via five gullies, and by late morning barely six hundred men had reached the higher ground. By noon, as the artillery fire took its toll and the Germans started to run out of ammunition, the Americans were able to clear some lanes on the beaches. They also started clearing the draws of enemy defences so that vehicles could move off the beach. The tenuous beachhead was expanded over the following days, and the D-Day objectives were accomplished by D+3.