Originally Posted by BritinAfrica
HMS Hood blew up because a shell from Bismark penetrated her deck armour and exploded in one of the magazines. She should have been refitted with heavier deck armour but operational and goodwill cruises kept her out of the dockyards.
I don't think there is much evidence that this was the case
An extensive review of each of these theories (except that of Preston) is given in Jurens. Its main conclusion is that the loss was almost certainly precipitated by the explosion of a 4 inch (102 mm) magazine, but that there are a number of ways in which this could have been initiated. In Jurens' opinion, the popular image of "plunging fire" penetrating deck armour of Hood is inaccurate, as by his estimation the angle of fall of Bismarck's 38 cm shells at the moment of the loss would not have exceeded about 14 degrees, an angle so unfavourable to penetration of horizontal armour that it is actually off the scale of contemporary German penetration charts. Moreover, computer-generated profiles of the Hood show that a shell falling at this angle could not have reached an aft magazine without first passing through some part of the belt armour. On the other hand, the 12 inch (305 mm) belt could have been penetrated, if the Hood had progressed sufficiently far into her final turn.
I'm all in favour of keeping dangerous weapons out of the hands of fools. Let's start with typewriters. Frank Lloyd Wright