As Andy points out, they passed the word up the chain. Rommel, who was in charge of the defense of Fortress Europe was on holiday back in Germany, had made statements that the first 24 hours of any invasion would be absolutely crucial. He too was not immediately informed of the invasion. When at last they told him, he was absolutely livid. Hitler believed that this landing (Normandy) was just a diversion and with held committing major forces to stem the hemorrhage. When a call went out for the 2nd Panzer Div (in the South of France) to move up, they stopped along the way to execute a village for terrorist activities. Their arrival was too little, too late. The Luftwaffe launched an Ardo recon. plane -- avgas was being rationed and so no flights were called up to strafe the troops on the beach. The Ardo flew over undetected and snapped some REALLY impressive shots which were sent back to Berlin. Those shots demonstrated clearly that this was indeed the main assault. Rommel was fired, von Runstadt was put in his place and shortly after that, he too was fired and then Model was given the job. Model was a fool, plain and simple. He failed to grasp the gravity of the situation, where as Rommel and von Runstadt saw clearly and dared speak the truth. For the Germans, their only real saving grace was that Montgomery had promised to take the rail/hiway junction within the first 16 hours. It took him over three weeks, and his dragging feet allowed the Germans plenty of time to lay waste to the port at Charbourge. Having been allowed that opportunity, they capitalized on that delay which meant that all Allied supplies coming in had to pass through the beaches of Normandy which then slowed the assault tremendously.