Set off explosive without gel and died (7)
I believe the answer is:
Here is my best explanation:
'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'.
(Other definitions for ignited that I've seen before include "Kindled", "fired", "Fired", "Caught fire", "Set alight", "Lit", "Set on fire", "Sparked off" and "Gin diet (anag.)".)