At 0630 hours on 6 June 1944, the US Army's 1st and 29th Infantry Divisions led the assault on Omaha Beach, the most strongly defended of the all invasion beaches. Supporting Allied bombers had mostly missed their targets, the offshore naval bombardment was hampered by poor visibility, and many elements of the first assault waves were swamped or sank, including amphibious tanks. The first waves of infantry waded ashore into a storm of German fire. In these first harrowing hours of 'Overlord', Lieutenant General Omar Bradley, commanding First US Army, seriously considered aborting the Omaha landing altogether. Yet despite appalling difficulties and heavy casualties, the US troops prevailed and a vulnerable bridgehead inland was established by the evening of 6 June. It was the hardest fight of D-Day.