it was the css hl hunly
The USS Housatonic, sunk by the Confederate submarine CSS Hunley.
The Confederate submarine, the Hunley was the first submarine to successfully sink a warship. It however, was dragged down to destruction during the battle in Charleston Harbor.
the siege
Nobody. The submarine was captured before it was sunk.
USS Thresher
There is no ship known, it is not the Lusitania, which was an English ship.
Submarines do get sunk in the sea.
The German submarine U-21 sank the British cruiser Pathfinder on September 5, 1914. U-21 survived the entire World War 1 but sank while sailing to port to surrender after war's end. The Confederate submarine Hunley sank a US Navy ship, but sunk herself for reasons that remain uncertain.
Lusitania
Yes
The Confederacy led in the experimentation with submarines. The most successful was the HL Hunley. This submarine sunk a Union warship however the sinking ship damaged the submarine that also sank.
German submarine ;