Complex sentence: On 20 July 1944 the Royal Navy destroyer HMS Isis was mined while at anchor in the Seine Bay, the loss was not discovered until the following morning, there were twenty survivors and German "human torpedoes" were suspected of sinking the warship.
Split into simpler sentences: On 20 July 1944, the Royal Navy destroyer HMS Isis was mined while at anchor in the Seine Bay. The loss was not discovered until the following morning; there were twenty survivors and German "human torpedoes" were suspected of sinking the warship.