 Very little went as planned during the landing at Omaha . Difficulties in navigation caused the majority of landing craft to miss their targets throughout the day . The defenses were unexpectedly strong , and inflicted heavy casualties on landing U.S. troops . Under heavy fire , the engineers struggled to clear the beach obstacles ; later landings bunched up around the few channels that were cleared . Weakened by the casualties taken just in landing , the surviving assault troops could not clear the heavily defended exits off the beach . This caused further problems and consequent delays for later landings . Small penetrations were eventually achieved by groups of survivors making improvised assaults , scaling the bluffs between the most heavily defended points . By the end of the day , two small isolated footholds had been won , which were subsequently exploited against weaker defenses further inland , thus achieving the original D @-@ Day objectives over the following days . 
