Frederick met Fermor's troops on the marshes outside the hamlet of Zorndorf, east of the Oder River. Frederick planned to take his enemy by surprise by marching around the Russian rear to the south under the cover of night; however, the next morning the Russian forces simply reversed direction and faced their foe, now to the south, once more. Although the Prussians lost the element of surprise, the Russians were now in a vulnerable position, as their backs now stood against the river and the surrounding swamp. On 25 August 1758, following 2 hours of bombardment, the Prussian left engaged the Russians in what quickly became a murderous exchange of volleys. However, Frederick's left column, intending to support attack on the Russian right, instead drifted towards the center and stalled out in the engagement. Fermor quickly took advantage of this and sent his cavalry charging through the weakened left flank and sent it backwards in disorder, but their advantage was neutralized by a prompt counterattack by the Prussian cavalry. The battle degenerated into disorganized attrition, and the two bloodied forces did not break off until night fell. Thus the Battle of Zorndorf ended with 30,000 casualties total out of a total of 80,000 men, and both sides withdrew by the next morning.