Did any and if so how many ships sank during WW1 and 2 because of natural causes? (eg massive waves, storms, Bermuda triangle, etc.)
Yes, there were plenty of ships lost to storms and grounding. Between the wars, the French lost a dreadnought battleship to an uncharted rock; that's the most dramatic case I can recall.
And I thought car accidents were bad! What a pileup! I heard the USS Memphis sank in 1916 in the Bermuda Triangle (or not) after encountering a massive wave.
Here's the US losses during WW II to storms. SS Truxtun (DD-229) and USS Pollux (AKS-2) ran aground during a storm in Placentia Bay, Newfoundland, and broke up in surf. 204 killed. 18 Feb. 1942. USS Warrington (DD-383) sank during hurricane off Florida. 248 drowned. 13 Sep. 1944. Task Force 38 struck by typhoon off the Philippines. Destroyers USS Hull (DD-350), USS Spence (DD-512), and USS Monaghan (DD-354) capsized and sank, at least 28 other vessels damaged. About 790 killed and 80 injured. 18 Dec. 1944. Task Force 38 struck by typhoon in Okinawa area. 36 ships damaged. At least 6 killed and 4 injured. 5 Jun. 1945.
I read bout this incident some years ago, and I've always been amazed that more men weren't killed. Richard Winer wrote a detailed account of this event in his book, "From the Devils' Jaw to the Devil's Triangle". Apparently, Point Honda is, or was, also known as "The Devil's Jaw."