For the next two months, AAF heavy bombers from England and Italy struck repeatedly at strategic targets deep in enemy territory. In addition, Italian-based fighters and bombers attacked shipping, railroads and highways to paralyze the German transportation network, thereby easing the task of Allied ground troops slowly advancing northward to Rome. At the same time, British-based fighters and bombers conducted concentrated attacks on V-1 launching sites on the French and Belgian coasts and against Luftwaffe airfields and coastal defenses.
As the date for the invasion of France approached, the AAF and RAF began a campaign to destroy the transportation network in northwestern France. Initially, railroad yards were heavily bombed, but when it became apparent that damage was being rapidly repaired, tactics were changed to "bridge busting." Hundreds of bridges were attacked across Belgium and northern France, and by D-Day, all 12 railroad and 14 highway bridges across the Seine River from Paris to Le Havre had been destroyed. German reinforcements of the Normandy coast following the invasion was to be most difficult.
