Detective's bloomer creating accident (8)
I believe the answer is:
disaster
'accident' is the definition.
(disaster is a kind of accident)
'detective's bloomer' is the wordplay.
'detective's' becomes 'dis' (Detective Inspector).
'bloomer' becomes 'aster' (aster is a kind of flowering plant).
'dis'+'aster'='DISASTER'
'creating' is the link.
(Other definitions for disaster that I've seen before include "terrible trouble" , "not a success!" , "Great tradegy or cataclysm" , "Calamity, tragedy" , "Catastrophe, tragedy" .)