B集團軍
On 1 April Army Group B found itself completely surrounded in the Ruhr by the U.S. First and Ninth Armies. Hitler's response was to declare the Ruhr a fortress, from which he commanded that there was to be no surrender or attempt to break out, in an order similar to that which he had issued at Stalingrad. He further ordered that its physical economic infrastructure—the heart of Germany's industrial power—be destroyed by Army Group B to prevent it falling into Allied hands. Model ignored these instructions.