<P> With the beach assault phase completed the RCTs reorganized into infantry regiments and battalions and over the course of the next two days achieved the original D - Day objectives . On the 1st divisional front the 18th Infantry Regiment blocked an attempt by two companies from the 916th and 726th Grenadiers to break out of WN - 63 and Colleville, both of which were subsequently taken by the 16th Infantry Regiment which also moved on Port - en - Bessin . The main advance was made by the 18th Infantry Regiment, with the 3rd battalion of the 26th Infantry Regiment attached, south and south - eastwards . The heaviest opposition was encountered at Formigny where troops of the 2nd battalion 915th Grenadiers had reinforced the headquarters troops of 2nd battalion 916th Grenadiers . Attempts by 3 / 26 and B / 18 with support from the tanks of B / 745 were held off and the town did not fall until the morning of June 8 . The threat of an armored counterattack kept the 18th Infantry Regiment on the defensive for the rest of June 8 . The 26th Infantry Regiment's three battalions, having been attached to the 16th, 18th and 115th Regiments the previous day, spent June 8 reassembling before pushing eastwards, forcing the 1st battalion of the German 726th Grenadiers to spend the night extricating itself from the pocket thus forming between Bayeux and Port - en - Bessin . By the morning of June 9 the 1st Division had established contact with the British XXX Corps, thus linking Omaha with Gold . </P> <P> On the 29th divisional front two battalions of the 116th Infantry Regiment cleared the last defenders from the bluffs while the remaining 116th battalion joined the Rangers in their move west along the coast . This force relieved the 2nd Ranger companies who were holding Pointe du Hoc on June 8 and subsequently forced the German 914th Grenadiers and the 439th Ost - Battalion to withdraw from the Grandcamp area which lay further to the west . Early on June 7 WN - 69 defending St. Laurent was abandoned and the 115th Infantry Regiment was therefore able to push inland to the south - west, reaching the Formigny area on June 7 and the original D - Day phase line the following day . The third regiment of 29th Division; the 175th, started landing on June 7 . By the morning of June 9 this regiment had taken Isigny and on the evening of the following day forward patrols established contact with the 101st Airborne Division, thus linking Omaha with Utah . </P> <P> In the meantime, the original defender at Omaha, the 352nd Division, was being steadily reduced . By the morning of June 9 the division was reported as having been "...reduced to' small groups' ..." while the 726th Grenadier Regiment had "...practically disappeared ." By June 11 the effectiveness of the 352nd was regarded as "very slight", and by June 14 the German corps command was reporting the 352nd as completely used up and needing to be removed from the line . </P> <P> Once the beachhead had been secured, Omaha became the location of one of the two Mulberry harbors, prefabricated artificial harbors towed in pieces across the English Channel and assembled just off shore . Construction of' Mulberry A' at Omaha began the day after D - Day with the scuttling of ships to form a breakwater . By D + 10 the harbor became operational when the first pier was completed; LST 342 docking and unloading 78 vehicles in 38 minutes . Three days later the worst storm to hit Normandy in 40 years began to blow, raging for three days and not abating until the night of June 22 . The harbor was so badly damaged that the decision was taken not to repair it; supplies being subsequently landed directly on the beach until fixed port facilities were captured . In the few days that the harbor was operational, 11,000 troops, 2,000 vehicles and 9,000 tons of equipment and supplies were brought ashore . Over the 100 days following D - Day more than 1,000,000 tons of supplies, 100,000 vehicles and 600,000 men were landed, and 93,000 casualties were evacuated, via Omaha . </P>

Who is responsible for guiding the invasion upon the beach heads in northern france