Anticipating a major attack, Steiner ordered the heavy weapons of the SS-Panzergrenadier Regiment Norge and the Danmark Regiment to be pulled together into two shock units. By the night of 28 July the battle had subsided. Grenadier Hill Preparatory fire The morning of 29 July began with preparatory artillery fire of 25,000 shells fired by the Soviets. The bombardment covered the Tannenberg Line in a dust cloud. The forest on the Sinimäed Hills was entirely destroyed, with the trees cut down to a height of 2–3 metres. While having a great psychological effect, the "Katyushas" or so-called "Stalin organs" were inaccurate, causing little damage to the well-dug-in German troops. The 70–80 German Nebelwerfers answered. This was followed by Soviet bombers trying to hit the last of the German troops, ducking down in their trenches. Dressed in camouflage uniforms, they remained unseen by the Soviet pilots. Soviet advance guards on the Grenadier Hill The attack of 6,000 Soviet infantry began at 09:00, supported by a regiment of nearly 100 tanks (most of them of the heavy IS-2 variety). They used their 122 mm guns to fire directly at the strongpoints showing any signs of life and destroyed the remaining bunkers. The remnants of the German advance guard were destroyed. The platoon commanded by Lt. Lapshin broke through to the top of the Grenadier Hill. Special courage was shown by Sgt. Efendiyev, who destroyed a German strongpoint on the hill. The Komsomol organiser, V.I. Lavreshin of the 937th Rifle Regiment, who had been marching ahead of his troops with a red flag in his hands, erected it at the summit. Attack of Soviet main forces The principle of the Soviet attack in the Sinimäed was an overwhelming frontal shock, with only a few of the attackers presumed to have reached the target. With artillery fire preventing reinforcements being sent in from the German rear, the Soviet 8th Army went on the attack and drove a wedge into the north flank of the 11th Infantry Division. The Soviet main tactical goal, the Grenadier Hill, was to be assaulted by the 6,000 troops of the 109th Rifle Corps. The 109th Rifle Division attacked Nederland, which was covering the hill from the north. The 120th Rifle Division hit the Grenadier Hill from the east. The 72nd Rifle Division assaulted the II Battalion, 3rd Estonian Regiment, which was defending the northern flank. The 117th Rifle Corps