ORIGINAL: mdiehl
Hood wasn't a BB and should not be on the list of BBs sunk by gunfire. It was a CB with that class' known deck armor weaknesses. Any of the larger bombs in the USN and IJNs arsenals could have penetrated Hood's deck armor....
And yeah, the last of those end-war Japanese BBs were not at sea. But as this thread was about whether or not a few bomb hits could do sufficient damage to a BB to sink one, I'm not sure the objection is germane. Those ships did have crews and were at action stations (and presumedly with watertight integrity and damage control teams on board) when they were sunk.
It's certainly true that Hood was a battlecruiser, but it's easy to misunderstand what that means. It does not imply a lack of protection, believe it or not. Really all it means, in Hood's case, is that she had cruiser-like speed. The battlecruiser term went through a spectrum of meanings; Hood herself was the ship that prompted the RN to use the term to indicate any fast capital ship. That's why you will find official RN documents referring to the early drafts of the modern KGV class battleships as battlecruisers. Terminology shifted again in the midst of the KGV design process, so she began construction as a battleship instead. Hood was arguably the best-protected ship in the RN at the time she entered service.
The two Fusos both sank in Surigao Strait, or Sergio Strait as Nik likes to call it. The similar Ise and Hyuga, though, were both victims at Kure. The bombs that sank them came not from B-29's but from carrier planes (Avengers?). This certainly proves that bombs could sink battleships, but I personally don't find it any more compelling than the Mitchell tests. The state of shipboard readiness was as good as possible under the circumstances, but the ships were completely swarmed, targeted by multiple dozens of bombs.