A force of six German destroyers set out on the moonlit night of 21-22nd February 1940 to intercept British fishing boats off the Dogger Bank on North Sea. Although the Kriegsmarine (German Navy) had been informed that the Luftwaffe intended to fly anti-shipping operations in the North Sea that night, the message had not been passed on to the task group. As the German force made their way through the narrow swept channel of their own minefield the German destroyer Z 1 Leberecht Maas was bombed by a Heinkel III; in two attacks she was hit three times and sunk.
In the following minutes there was confusion in the remaining five destroyers, who had apparently not seen the second attack by the aircraft. In the confined area of the swept channel they faced considerable dangers from their own mines as they tried to rescue the crew from the freezing cold waters. The situation was then compounded by the belief that they were under torpedo attack. The Theodor Riedel interpreted hyrophone sounds as a submarine but she was travelling too slowly when she dropped her depth charges and she damaged her own hull and steering. The German destroyer Max Schulz was then blown up in another large explosion appearently hitting a mine.
The Erich Koellner , Friedrich Eckoldt and Richard Beitzen put out their boats to pick up survivors. However, just as they reached the men in the water, another submarine was believed sighted (there was actually no British submarine on the area ) and they were ordered away from the rescue at speed. The small boat was still attached to the stern of the Erich Koellner with a rescue party in it, as the destroyer sped off this boat capsized and they were all lost. Ultimately there were no survivors from the Max Schulz , unable to survive in the icy waters whilst the other ships spent twenty-five minutes looking for a submarine, and they rescued only sixty from the Leberecht Maas . In total 578 men were lost.
Meanwhile the Luftwaffe were reporting that they had bombed a single ship some 50km away, and were querying a teleprinter request from the Kriegsmarine to provide a dawn escort for a returning task force, since they were not aware of any German ships in the area in the first place. It was to take some time before the subsequent German enquiry was able to piece together what had happened. Loss of two valuable destroyers (German Navy only had 24 destroyers at this stage of war) and almost 600 naval personel due to discoordination was sufficient enough for German Navy to hush up whole matter.