The hazard of a mine collapse (7)
I believe the answer is:
pitfall
'the hazard' is the definition.
(I've seen this before)
'a mine collapse' is the wordplay.
'a mine' becomes 'pit' (down the pit).
'collapse' becomes 'fall' (I've seen this in another clue).
'pit'+'fall'='PITFALL'
'of' is the link.
(Other definitions for pitfall that I've seen before include "Trap in the form of a concealed hole" , "Unexpected problem" , "Hazard" , "Unforeseen difficulty" , "Unsuspected danger or difficulty - for miner?" .)