A little nostalgia of the colonial past. Anderson Bridge and Fullerton Building, now Hotel, in the background. Used to be the GPO. And the tongkang is now a pleasure cruiser for sightseers instead of goods carrier or bumboats.
Look at the picture carefully. Look at how the steel plates folded, outwards and upwards. It looks like the explosion was from inside or from below. An internal accidental, hitting a mine below?
If it was hit by a torpedo, the steel plates would be folding outwards from one side. You make your conclusion.