Blast occurs, exploding shelters (5)
I believe the answer is:
curse
'blast' is the definition.
(thesaurus)
'occurs exploding shelters' is the wordplay.
'shelters' says the answer is hidden in the clue.
'CURSE' is hidden within 'occurs exploding'.
(Other definitions for curse that I've seen before include "Malediction or expletive" , "Profanity" , "Profane or obscene expression" , "It's bad spelling" , "Invocation of evil; swear" .)