For example, the 4th Panzer Division fell into an ambush set by Dmitri Leliushenko's hastily formed 1st Guards Special Rifle Corps, including Mikhail Katukov's 4th Tank Brigade, near the city of Mtsensk. Newly built T-34 tanks were concealed in the woods as German armor rolled past them; as a scratch team of Soviet infantry contained their advance, Soviet armor attacked from both flanks and savaged the German Panzer IV tanks. For the Wehrmacht, the shock of this defeat was so great that a special investigation was ordered. Guderian and his troops discovered, to their dismay, that the Soviet T-34s were almost impervious to German tank guns. As the general wrote, "Our Panzer IV tanks with their short 75 mm guns could only explode a T-34 by hitting the engine from behind." Guderian also noted in his memoirs that "the Russians already learned a few things." In 2012, Niklas Zetterling disputed the notion of a major German reversal at Mtsensk, noting that only a battlegroup from the 4th Panzer Division was engaged while most of the division was fighting elsewhere, that both sides withdrew from the battlefield after the fighting and that the Germans lost only six tanks destroyed and three damaged. For German commanders like Hoepner and Bock, the action was inconsequential; their primary worry was resistance from within the pocket, not outside it. Other counterattacks further slowed the German offensive. The 2nd Army, which was operating to the north of Guderian's forces with the aim of encircling the Bryansk Front, had come under strong Red Army pressure assisted by air support. According to German assessments of the initial Soviet defeat, 673,000 soldiers had been captured by the Wehrmacht in both the Vyazma and Bryansk pockets, although recent research suggests a lower—but still enormous—figure of 514,000 prisoners, reducing Soviet strength by 41%. Personnel losses of 499,001 (permanent as well as temporary) were calculated by the Soviet command. On 9 October, Otto Dietrich of the German Ministry of Propaganda, quoting Hitler himself, forecast in a press conference the imminent destruction of the armies defending Moscow. German civilian morale—low since the start of Barbarossa—significantly improved, with rumors of soldiers home by Christmas and great riches from the future "Lebensraum" in the east. However, Red Army resistance had slowed the Wehrmacht.