On the eastern front, progress was very slow. The Russian army was heavily dependent upon its main magazines in Poland, and the Prussian army launched several successful raids against them. One of them, led by general Platen in September resulted in the loss of 2,000 Russians, mostly captured, and the destruction of 5,000 wagons. Deprived of men, the Prussians had to resort to this new sort of warfare, raiding, to delay the advance of their enemies. Nonetheless, at the end of the year, they suffered two critical setbacks. The Russians under Zakhar Chernyshev and Pyotr Rumyantsev stormed Kolberg in Pomerania, while the Austrians captured Schweidnitz. The loss of Kolberg cost Prussia its last port on the Baltic Sea. In Britain, it was speculated that a total Prussian collapse was now imminent.