Misfortunes of relaxed obligations (10)
I believe the answer is:
casualties
'misfortunes' is the definition.
(I know this)
'relaxed obligations' is the wordplay.
'relaxed' becomes 'casual' (I've seen this before).
'obligations' becomes 'ties' (I've seen this in another clue).
'casual'+'ties'='CASUALTIES'
'of' is the link.
(Other definitions for casualties that I've seen before include "Victims" , "Injured people" .)