First Neutral Ship Sunk in WWI? Not the Lusitania!

When I asked Google recently to identify the first vessel of a neutral nation to be sunk during in the Great War, the AI gizmo that now provides quickie answers at the top of your search results responded with RMS Lusitania, sunk 7 May 1915. This left me perplexed because Great Britain was decidedly not neutral during the war. So, I kept digging and discovered this Swedish collier that  clearly belonged to a company within a neutral nation and flew the flag of a neutral country. Plus, it was sunk befoe the Lusitania:

SS Hanna, Sunk 13 March 1915

Over a century later, though, the exact circumstances are still murky. Here's what the Scarborough Maritime Heritage Centre has to say about it:

The Swedish collier Hanna has variously been reported as being torpedoed and mined. The ship’s second officer claims to have seen the wake of a torpedo, but as no submarine was spotted, it is probable that the ship struck one of German cruiser SMS Kolberg’s mines as the ship was within the area where the minefield had been laid. Indeed, the ship’s first engineer, who had served in the Swedish navy for five and half years, was convinced that the ship had struck a mine. 

The Hanna was bound for Las Palmas with coal from the Tyne. Around 01:40 on 13 March 1915. A huge explosion quickly followed, which killed six of the eight men asleep in the forecastle. The explosion occurred near the foremast and the ship remained afloat for half an hour. The two survivors in the forecastle, although badly injured managed to escape. The Hanna began to sink immediately and the surviving crew took to the lifeboats. They were picked up by the steamer Gylier and landed at Alexandra Dock, Hull. 

The Case for a mine: On 16 December 1914, the German Navy had attacked several British ports and laid mines as part of their mission. As the German battlecruisers bombarded the streets of Scarborough, the light cruiser Kolberg was laying a minefield in the waters between Cayton Bay and Gristhorpe. Over three months, between 16 December 1914 and 13 March 1915, the mines would sink twenty ships and cause the deaths of 113 sailors; six times more than were killed on land during the bombardment.

The captain also reported that the night was so dark that it would have been impossible to see anything in the water. The German policy of sinking all vessels in the North Sea was not in force at this time, which suggests that a mine may have been the reason for the sinking.

Why a torpedo?:  The second officer was on watch and reported that he saw the wash from a torpedo on the starboard side. Consequently, some sources still report the sinking as due to a torpedo from a U-boat. I wasn't there, but that's not the way I'd bet.