"Obama downplayed any suggestion that the recent controversies surrounding his campaign would torpedo his candidacy."
The ship was sunk by an enemy torpedo.
a small fast unarmored and lightly armed torpedo boat; P(ropeller) T(orpedo) boat.
I would also like to point out the battle of Samar as an interesting case study of daylight destroyer torpedo attack disrupting cruiser and even battleship battle formations.
The destroyer's armament consist of several small cannon, two torpedo tube and a number of anti-craft gun.