The final stage of the Rhineland Offensive was the crossing of the fabled river itself. It was clear to everyone that the Rhine was the last major natural obstacle to the Allied advance into Germany. The crossing of the Rhine between Rees and Wesel (Operation Plunder) was part of several coordinated Rhine crossings. The actions started late on 23 March 1945. It was an operation of large numbers. A million soldiers from three countries participated. The Allies gathered over 4.000 pieces of artillery on the West bank of the river while over 250.000 tons of supplies were amassed near the front. The preparations were obscured from German view by the largest smoke screen ever laid. In support of the Rhine crossing, Operation Varsity, the largest airborne operation performed in a single day, took place. 14.000 paratroopers were dropped east of the Rhine behind enemy lines to deepen the Allied bridgehead and to knock out German artillery targeting the Rhine. Operation Plunder went like clockwork. German resistance was completely broken by the artillery barrage and in the first two hours of the operation the Allies lost only 31 men. Some of the casualties of the Operations Varsity and Plunder are buried at the Reichswald Forest Cemetery. After the establishment of the first bridgeheads it took engineers of the 9th U.S. Army just nine hours to bridge the river. Winston Churchill was present at the headquarters of Field Marshall Montgomery to witness the start of the final stage of the war in Germany. With the Allies crossing the Rhine, the days of the Third Reich were numbered.