K is a consonant that we get from the Greeks, but it can be traced away back beyond them to the Cerathians,

K is a consonant that we get from the Greeks, but it can be traced
away back beyond them to the Cerathians, a small commercial nation
inhabiting the peninsula of Smero. In their tongue it was called
_Klatch_, which means "destroyed." The form of the letter was
originally precisely that of our H, but the erudite Dr. Snedeker
explains that it was altered to its present shape to commemorate the
destruction of the great temple of Jarute by an earthquake, _circa_
730 B.C. This building was famous for the two lofty columns of its
portico, one of which was broken in half by the catastrophe, the other
remaining intact. As the earlier form of the letter is supposed to
have been suggested by these pillars, so, it is thought by the great
antiquary, its later was adopted as a simple and natural -- not to say
touching -- means of keeping the calamity ever in the national memory.
It is not known if the name of the letter was altered as an additional
mnemonic, or if the name was always _Klatch_ and the destruction one
of nature's pums. As each theory seems probable enough, I see no
objection to believing both -- and Dr. Snedeker arrayed himself on
that side of the question.
-- Ambrose Bierce, "The Devil's Dictionary"