We’ve all become used to computer-generated scenes of disaster — of meteors thudding into the Earth with the force of a thousand nuclear explosions, seas engulfing cities, or people flash frozen mid-stride.

There was something cinematic and unreal about the video from the Himalayas this week, showing what can be described as a flood only if one wants to be euphemistic. It was a disaster the scale of which seemed, in the earliest moments, to make it the product of a wild fictional imagination.