"Ashes were already falling, not as yet very thickly. I looked round: a dense black cloud was coming up behind us, spreading over the earth like a flood.'Let us leave the road while we can still see,'I said,'or we shall be knocked down and trampled underfoot in the dark by the crowd behind.'We had scarcely sat down to rest when darkness fell, not the dark of a moonless or cloudy night, but as if the lamp had been put out in a closed room.
You could hear the shrieks of women, the wailing of infants, and the shouting of men; some were calling their parents, others their children or their wives, trying to recognize them by their voices. People bewailed their own fate or that of their relatives, and there were some who prayed for death in their terror of dying. Many besought the aid of the gods, but still more imagined there were no gods left, and that the universe was plunged into eternal darkness for evermore".
That's about it if you want to have an account. One can imagine but only in the context that our eyes have seen volcanoes erupt and have enough movie references so we kinda "get it" as to the horror. Tidal waves in movies tend to be of the Poseidon Adventure scale with a 100 feet of water barrelling towards a ship or shore and, like a broom, everyone and thing is swept clean. Japan's tragedy seemed different - like some ooze, some spilled bucket of mud, that just came coming out of an endlessly deep bucket. The film of the wave at the airport is a perfect example:
We can watch nearly endless scenes of this tragedy - captured by all manner of electronic device and reported virtually as a play by play of some natural sporting event. Like the Challenger explosion or the airplanes in 9-11, the visuals are burned into our brains and an endless supply of new angles and new footage appears as if in an endless mailing with responders putting on the stamp and eventually dropping the views at the post office.
I'm not at all sure that I have more comfort in seeing and therefore knowing.