Determination of town on Etna destroyed (8)
I believe the answer is:
tenacity
'determination' is the definition.
(tenacity is a kind of determination)
'town on etna destroyed' is the wordplay.
'town' becomes 'city' (I've seen this in other clues**).
'on' is a charade indicator (letters next to each other).
'destroyed' is an anagram indicator.
'etna' is an anagram of 'tena'.
'city' put after 'tena' is 'TENACITY'.
'of' is the link.
(Other definitions for tenacity that I've seen before include "Doggedly pursuing" , "Persistence, resolution" , "Firm grasp" , "Bulldog quality" , "Persistence in holding on" .)