D-Day at Utah began at 01:30, when the first of the airborne units arrived, tasked with securing the key crossroads at Sainte-Mère-Église and controlling the causeways through the flooded farmland behind Utah so the infantry could advance inland. While some airborne objectives were quickly met, many paratroopers landed far from their drop zones and were unable to fulfill their objectives on the first day. On the beach itself, infantry and tanks landed in four waves beginning at 06:30 and quickly secured the immediate area with minimal casualties. Meanwhile, engineers set to work clearing the area of obstacles and mines, and additional waves of reinforcements continued to arrive. At the close of D-Day, Allied forces had only captured about half of the planned area and contingents of German defenders remained, but the beachhead was secure.