Set off explosive without gel and died (7)
I believe the answer is:
ignited
'set off' is the definition.
(I've seen this before)
'explosive without gel and died' is the wordplay.
'explosive' becomes 'gelignite' (gelatin-based explosive substance).
'without' is a deletion indicator.
'and' is a charade indicator (letters next to each other).
'died' becomes 'd'.
'gelignite' with 'gel' removed is 'ignite'.
'ignite'+'d'='IGNITED'
(Other definitions for ignited that I've seen before include "Caught fire" , "Kindled" , "Sparked off" , "fired" , "Lit" .)