 On 19 September , Königsberg left the Rufiji and arrived off Zanzibar the following morning . She opened fire at a range of about 7 @,@ 000 meters ( 23 @,@ 000 ft ) at 05 : 10 , starting the Battle of Zanzibar ; within 45 minutes , Pegasus caught fire , rolled over to port , and sank . Crewmen aboard Pegasus had raised a white flag , but it could not be seen aboard Königsberg due to the heavy smoke . Pegasus 's crew suffered 38 dead and 55 wounded , while Königsberg was undamaged and had no casualties . After sinking Pegasus , Königsberg bombarded the wireless station and dumped barrels filled with sand into the harbor entrance to simulate mines . While leaving the harbor , Königsberg spotted the picket ship Helmut and sank her with three shells . 
